Yes, PM S02E07
THE NATIONAL EDUCATION SERVICE
B:The Chief Whip and Party Chairman to see you.
PM:Take a seat, I’ll be right with you.Bernard, take a seat. I want you here for this meeting.
B: But, isn’t this a party matter?
PM: It’s also a government matter. It’s about our education policy.
B: The government’s or the party’s?
PM: It’s the same thing.
A1: With respect, PM, they’re not the same thing.
A2: That’s why we want the meeting.
B: Well, it seems to be a party…
PM: Bernard, sit! Stay!
Now, what’s the problem?
A1: Education.
PM: Now, what do you think I can do about it?
A2: You’re the PM.
PM: Yes, I know, and I have no direct control over education, as such, I mean I don’t control the curriculum, I don’t control the exams, Idon’t control the choice of head teacher, nothing.
A1: But the voters are holding you responsible for everything was going wrong, you do have influence.
PM: And I’m absolutely fled up with it. When I became PM, I thought Iwas had get power. What have I got? I’ve got influence, that’s all. I’ve got no power over the police, the rates, EEC directives, European courts, our courts, the judges, NATO.
What have I got the power to do?
A1: Have the power to lose us the next election.
A2:Which you will if you don’t do something about education.
A1:The voters want something done about low academic attainment, none competitivelythought, sex education.
PM:I’m not against sex education.
A1: Oh I’m not against children being taught the facts of life in the classroom, but not homosexual technique. Or heterosexual technique comes to that.
PM: Well where should they learn it then?
A1: Behind the bike sheds like we did!
PM: Did you?
A2: Never mind sexual technique. Some of our schools are teaching more Hindi than English.
PM: I know the English is more important than Hindi, but Idaren’t say so in public, I’d be accused of racism.
A2: Yeah, but I…
PM: Last week when I met the Ethnic Awareness Council, I happened to glance at my watch when a black woman delegate was speaking, I was immediately accused of racist body language.
B: And sexist body language.
PM: Anyway I get the message. What do you want me to do?
A1: We want to you get a grip on education.
A2: Get Henry to do something about the Department of Education and Science. PM: He won’t. They’ve got him completely house-trained.
A2: Then sack him.
PM: I can’t have another Cabinet convulsion, not yet.
A1: Then invite the leader of the opposition’s wife here.
PM: What can she do?
A1: Start measuring up for carpets and curtains.
B: Yes, right, fine. This afternoon?
H: Bernard, I believe the Prime Minister wants to see me.
B: Yes, Sir Humphrey.
H: What’s his problem?
B: Education.
H: Well, i t’s a bit late to do anything about that now.
B: No, no, the education system.
H: I see. Well it’s be late to do anything about that either.
B: Well he thinks he’s going to lose the next election.
H: Well worse things could befall the nation.
B: He can’t ignore facts.
H: If he can’t ignore facts, he’s got no business being a politician. Anyway, Bernard, he’s got nothing to worry about. The education system does all the most parents require of it, keeps children out of mischief while they’re at work.
B:Yes, but that paper the Party Chairman showed the PM suggests the whole the comprehensive system is break down, isn’t it?
H: Bernard, I never thought to hear such language from a loyal member of the Civil Service! Have you got at by the enemy?
B: You mean the Russians?
H: No, Bernard, Idon’t. I mean the Prime Minister’s political advisor, that Wainwright female.
B: But comprehensive education was an experiment, sure it ought to be validated. H: Yes, of course, but not invalidated.
B: But if it was introduced to improve educational standards.
H: Whatever gave you that idea?
B: You mean it was to get rid of class distinction?
H: Precisely!
B: So that all children…
H: Children? Who mentioned children?
B: But I just thought...
H: The Department of Education never mentions children! No, no, no, no, Bernard. It was to get rid of class distinction in the teaching profession. Improve the living standard of teachers, not the educational standards of children. Bring the NUT teachers in the primary and secondary mountains up to the salary level of their
rivals in the National Association of Schoolmasters in the grammar schools.
B: But the Department…
H: Bernard, when there is a Labour government, the Education Department says the comprehensives abolish the class system, and when there’s the Tory government, they say that it’s the cheapest way providing message education. To Labour, we explain that selective education is divisive, and to the Tories we explain that it is expensive. That way, we have a happy relationship with the NUT, and we educate our own children privately.
B: But if the government wants change…
H: The teaching unions don’t.
B: But isn’t it our job to persuade unions to accept government policy?
H: No, Bernard, it is our job to get the government to accept union policy, and since government change policy all the time, and unions never change their policy at all, in practice common century require that it is the government who must be brought in line with the unions.
B: Yes, PM? Oh, fine. He can see you now.
Sir Humphrey, he’s very worried that he seems responsible for something he can’t change.
H:Yes, I’m sure. Responsibility without power-the prerogative of the eunuch throughout the ages.
Good morning, PM.
PM: Good morning, Humphrey. What there were you say?
H:Oh, nothing, PM. I understand that you’re worried about the local education authority.
PM: No, Humphrey, I’m worried about the Department of Education and Science. H: Indeed? In my opinion, the DES does a splendid job.
PM:Look, what happened to education in this country. This is a question from a Religious Studies paper, “Which do you prefer-atom bombs or charity? ”Even
math become politicized. “If it costs 5 billion pounds a year to maintain Britain’s nuclear defences and 75 pound a year to feed a starving African child, how many African children could be saved from starvation if the Minister of Defence abandoned nuclear weapons?”
H: That’s easy, none. They’d spend it all on conventional weapons. In any case, it’s just a sum. Five billion divided by 75.
PM: But the children aren’t learning how to do the sums.
H: No, indeed. But the local education authorities might argue that they don’t need to know how it’s done.
PM:Look, we were all thought basic arithmetic, weren’t we?
H: Were we? What’s 3,947 divided by 73?
PM: Err… Oh, I’d need a pencil and paper to do that.
No, never mind. I could do it when I left school.
H: But now you’d use a calculator.
PM: That’s not the point. I mean, look at Latin. Hardly anybody knows that now.
H: “Tempora mutantur, nor et mutanur in illis.”
PM: What?
H: Time change and we change with the times.
PM: Oh, precisely.
H: Si tacuisses, philosophus manisses.
PM: What does that mean?
H:“If you kept your mouth shout, we might thought you were clever.”
PM: I beg your pardon?
H: Oh, not you, PM. No, that’s the translation.
B: No one would ever have thought Sir Humphrey was saying that about you.
H: Go away, Bernard, please.
PM: I don’t believe it, Humphrey. You had a conventional strict academic upbringing.
Are you denying the value of it?
H: But what’s the use of it? I can’t even call upon it in conversation with the PM of Great Britain.
PM: Education in this country is a disaster. We supposed to be preparing children for working life, three quarters of the time they’re bored stiff.
H: Well, I should thought being bored stiff for the three quarters of the time was an excellent preparation for working life.
PM: The school leaving age was raised to 16, so they could learn more, now they’re learning less.
H: We didn’t raise it to they’d able to learn more. We raised it to keep teenagers off the job market, and hold down the unemployment figures.
PM: Are you saying there’s nothing wrong with education in this country?
H: No, of course not, PM. It’s a joke. It’s always been a joke, and as long as you leave it in the hands of local councillors, it will remain a joke. I mean half of them are your enemies anyway and the other half of sort of friends make you prefer your enemies.
PM: What are you saying?
H:I’m saying that education will never get any better as long as it’s subject to all that tomfoolery in the town halls. I mean just imagine what will happen Iyou put defence in their hands of local authorities.
PM: Defence?
H: Yes, give the local councils 100 million each and ask them to defence themselves, we would never to worried about the Russians, we’d have a civil war in three weeks!
PM:You just being silly.
H:Am I? PM, well, that’s what happen to education, and why? Because nobody thinks education is serious the way defence is serious.
PM: You mean that’s why civil defence left the hand of local authorities?
H:Of course. Because everybody knows it’s a joke. You just don't have important matters in the hand of those clowns. And as you’ve left education to them, you have attached little importance to it.
PM: I think it’s extremely important. It could lose me the next election.
H: In my naivety, I thought you were concerned about the future of our children.
PM: Yes, that too. After all, they get the vote at 18.
H: Well, then, PM, then centralise. Take it away from the local councils. Put it under the Department of Education and Science, you could actually do something about it.
PM: Do you think I could? Grasp the nettle, take the bull by the horns?
B: PM, you can’t take the bull by the horns if you’re grasping the nettle.
PM: Oh, really, Bernard?
B: Oh, I mean was if you grasp the nettle with one hand, you could take the bull by one horn with the other hand, but not both horns because your hand isn’t big enough, and if you did take the bully by one horn, it would be rather dangerous because… well, it was just mixed metaphors, since we were discussing education, I…I do…
Thank god! Yes, oh, it’s your, your political advisor outside.
PM: Send her in, would you, Bernard? Humphrey, thank you.
H: Thank you, PM.
PM: You’ve given one much food for thought.
H: in that case, PM, bon appetit.
Dear lady.
PM: Yes, Dorothy?
D: My notes from the program to your tour of the north-west.
B: PM, only this is to hospital and factories, PM.
PM: Hmm, yeah, drumming up notes in marginal constituencies.
B: No, PM.
PM: Why not?
B: Well, I’m coming with you if it’s a government tour. But if it’s canvassing marginal, it’s a party event. I can’t come and the Treasury can’t pay.
D:It’s a government visit, Bernard. It’s pure coincidence that all the stop-offs are in marginal.
B: Oh, well, that’s all right, then.
PM: That’s OK. Dorothy, what can I do about education? Quickly.
D: You mean do or appear to do?
PM: Oh, appear to do, I can’t do, obviously.
D:Well, oh, in the short term, we could get you on TV associated with something good and successful in education.
PM: Good, is there something?
D: Well, I had thought of this for your schedule. You could fit it in.
PM: St Margaret’s School Young Enterprise Scheme.
D: Yes, the school is set up its own manufacturing and trading company. They make cheeseboards, paperweights, toast racks, and so on. Mark and sell them and track the operation in their math and business-study classes. They involved local businessmen. Parents help too.
PM: Sounds great, does it cost a lot?
D: No, they give the money to local charity.
PM: Fine, I’ll do it. Make sure the TV crews have plenty of time to cover me… oh, cover the event, probably. Write me a speech with a snappy, 20 second piece for the news polities. That should win back a few seats.
B: PM.
PM:Give a lead to those responsible for the nation’s education, Bernard.
B:Of course, PM.
NEWSREADER: And finally this morning, the PM visited St Margaret’s School on his north-western tour. The school has set up it only a little manufacturing business where the children make a variety of goods in the school carpentry shop for sellingthe local community. The children do their own sales and marketing, and use the experiences they gain from the enterprise as a basis for their math and business studies. The PM was presented with an example of the school’s output. PM: And in conclusion, I must congratulate you on all the hard work, the discipline and the success of your enterprise. You’ve set an example in British education which other schools would do well to follow. We need more schools like St
Margaret’s, and I shall always treasure your present. No PM ever lost a sear if he could help it!
NEWSREADER: And that was the six o’clock news from the BBC.
PM: I thought that was OK, didn’t you?
D: Fine.
PM:My joke went down well.
D: My joke!
PM: Better than Channel 4 coverage anyway. They didn’t describe it as the PM’s tour of the north-west. They said,”Jim Hacker touring the marginal constituencies.”
A: That’s true, isn’t it?
PM: Yeah, but they shouldn't say it like that. That’s biased reporting!
A: Reporting the facts?
PM: Anyway, there’s nothing wrong with visiting the marginal.
A: But what they said was still true.
PM: But it was still biased to say it!
A: Oh, darling, I’m not interested your paranoia, I was interested in that school.
D: Yes, parents queue up to get their children into it.
A: What a pity they can’t all get in.
More coffee?
PM: Hmm.
D: Lovely.
A: Why can’t more parents send their children there?
PM: No room.
D: There is room. Actually, school numbers are falling.
PM: Yeah, but that mean poaching the other schools.
A: So what’s wrong with that?
PM: Well, the other schools wouldn’t have enough people so they have to close.
A: Great! St Margaret’s could take over their buildings.
PM: Oh, darling, couldn't do that, wouldn't be fair.
A: Who to?
PM: The teachers in the schools that had to close.
A: But the good teachers will be taken on by the popular school. They’ll be needed. PM: What about the bad teachers? It wouldn't be fair on them.
A:What about being fair on the children or rather bad teacher’s jobs more important?
PM: Darling, it’s… it’s no good, no way. Who’s to say who are the bad teachers? It just wouldn't work.
A: Why not?
PM: Well… it wouldn't work.
D: Why not?
PM: What do you mean?
D: Well, suppose schools were like doctors. I mean after all, under the National Health Service you can choose whichever doctor you like to go to, can't you?
PM: Yes.
D: And he gets paid per patient. Well, why don’t we do the same with schools? Have
a National Education Service. The parents could choose the schools they want,
and the school get paid per people.
A: Exactly!
PM: There’d be an outcry.
D: From the parents?
PM: Well, not from the parents, from the Department of Education.
D: Well, I see. And who has the most votes?
PM: No, the DES would block it.
D: Fine, get rid of them.
PM: What?
D: Get rid of the Department of Education.
PM: I don’t understand you.
D: Get rid of it abolish it, remove it, expunge it, eliminate it, eradicate it, exterminate it!
Get rid of it!
PM: Get rid of it?
D: Yes.
PM: I couldn't do that.
D: Why not? What does it do?
PM: I could do that. Local government could administer the lot. We could have a National Board of School Inspectors. I could send that house-trained idiot Henry to the House of Lords. Golly, I wonder what Humphrey will say.
D: Whatever he says, I want to be there when you tell him.
PM: To witness the clash between the political will and the administrative will?
D:I think it will be the clash between the political will and the administrative won’t.
H: You sent for me, PM?
PM: Oh, Humphrey, come in. sit down. I just want to bounce an idea off. I’ve realised how to reform the educational system.
H: Excellent, PM.
PM: I’m going to let parents move their children to school they want.
H:Well, you mean, after application, scrutiny, tribunal hearing and appeals procedures?
PM: No, just move them whenever they want to.
H: I’m sorry, I don’t quite follow.
D: This government will let parents decide which school to send their children to. H: PM, you can’t be serious!
PM: I am.
H: But it’s preposterous!
D: Why?
H: You can’t expect parents to make these choices. I mean how on earth would parents know which schools are best?
PM: Which school did you go to, Humphrey?
H: Winchester.
PM: Was it good?
H: Oh, excellent, of course.
PM: Who chose it?
H:My parents, naturally. Now, that’s different, PM. My parents were discerning people. You can’t expect ordinary people to know where to send their children. D: Why not?
H: Well, how could they tell?
D:They tell if their kids could read, write and do sums, they could tell their neighbours what happen about school, and they could tell if the exam results were good.
H: Exam results aren’t everything, PM.
D:That’s true, and those parents who don’t want to academic education for their children can choose progressive schools.
H:But parents have no qualifications to make these choices. I mean teachers are professionals. Parents are the worst people to bring up children. They’ve no qualifications, no training. You don’t expect untrained teachers to teach. The same should apply to parents.
PM: You mean, before being have children, they should be trained?
H: No, that’s no problem. They've all been trained to have kids. Sex-education classes have been standard for some years.
PM: See, well, perhaps we could do better. Before people relived have children, we should make them sit exams, written and practical, perhaps both. And then they could be issued with breeding licences.
H: Oh, very droll, PM. No but I’m being serious. It’s looking after children that parents are not qualified for. That’s why they have no idea which schools to choose. It couldn't work.
D:Then how does the Health Service work? People choose their family doctor without having medical qualifications.
H: Ah, yes, well, that's different.
D: How?
H: Well, doctors are… The patients aren’t parents, dear lady.
D: Oh, really? What makes you think that, Humpy?
H: Not as such. In any case, as a matter of fact, I think letting people choose doctors is
a very bad idea, very messily. Much tidier to allocate people to GPs, much fairer.
Then everyone has an equal chance of getting the bad doctors.
PM: I see.
H: In any case, we’re not talking about hospital, we’re talking education. And with respect, PM, I think that the DES will react with some caution to your rather novel proposals.
PM: You mean they'll block it.
H:I mean they will give it more serious urgent consideration, and insist on a thorough and rigorous examination of all the proposals, allied to a detailed feasibility study and budget analysis, perform producing a consultative document for consideration, and seeking comments and recommendations to be included in
a brief for a series of working parties, who will produce individual studies which
will provide the background for a more wide-ranging document, considering whether or not the proposal should be taken forward the next stage.
PM: You mean they'll block it.
H: Yeah.
PM: No problem.
D: We thought you’d say that.
PM: We have a solution.
H: Oh, yes?
PM: We’ll abolish the DES.
H:I’m sorry?
PM: We’ll abolish it.
H: Abolish it?
D: Why not?
H: Abolish Education and Science?! That’d be the end of civilisation as we know it!
PM: We only abolish the department. Education and Science will flourish.
H: Without government department? Impossible!
D: Humphrey, government departments are tombstones. The Department of Industry marks the grave of industry, the Department of Employment marks the grave of employment, the Department of Environment marks the grave of environment.
And the Department of Education marks where the corpse of British education is buried.
PM: What does the DES do? What’s it for? What’s its role?
H:I hardly know where to begin! PM. It lays down guidelines, it centralises and channels money into local education authorities and University Grants Committee.
It sets standards!
PM: Does it lay down the curriculum?
H: No, but it would like to!
D: Does it select and change head teachers?
H: No…
PM: Does it maintain school building?
H: No…
D: Does it set exam?
H: No…
PM: Does it choose the children?
H: No, but…
PM: Well how does it affect what my child does at school?
H: He supplies 60% of the cash.
D: Why can’t the cash go straight from the Treasury to the schools or the University Grants Committee? I mean do we really need 2,000 civil servants to funnel money from A to B?
H: The DES also creates a legislative framework for education.
PM: There’s not much legislation, surely. Environment could do that. They deal with other local authority matters.
H:PM, you can’t be serious! Who would assess forward planning and staffing
variations, variations in people population, density of schooling required in urban and rural areas? Who would make sure everything ran properly?
D: 2,500 private schools seem to solve these planning problems everyday for week, Humphrey, without any help from the DES. They simply respond to changing circumstances, supply and demand. It’s easy.
H: Who would plan for the future?
PM: Are you saying the education in British today is what the department planned? H: Well, of… No, of course not!
PM: Is there anything else that the DES does?
H: Well, it… it…
PM: Well, we don’t need it, then, do we? QED.
H: But…
PM: Quod erat demonstrandum.
A:I really… quite unthinkable. Once they start abolishing departments, the civilisation crumble.
H: Barbarians at the gates.
A: The return of the Dark Ages.
H: Ah… Did anything like this crop up when you were Cabinet Secretary out?
A: No, we let them amalgamate departments, but that worked very well.
H:Yes, quite. You keep the existing staff, put an extra layer of coordinating management at the top.
A:Exactly. But you have to stop the liquidation of the Department of Education, Humphrey. Have you tried discrediting the person who proposed it?
H: Well, no point. It was the Wainwright female, so he’s passing it off as his own idea. A: Discrediting the facts behind it?
H: Well, it’s a political idea, so obviously facts don’t come into it.
A: Massaging the figures?
H: No figures are involved. But it’s hard to get the PM to see that it’s a bad idea.
A: Of course. It’s actually a very good idea. It just mustn’t happen.
H: I wonder whether we oughtn’t to play along with it-in the interests of the nation’s children.
A: Never mind the nation’s children. What about our colleagues at the Department of Education?
H: Yes, of course. Sorry.
A: Humphrey, let’s be clear about this. The only people who’ll like this idea are the parents and the children. Everyone who counts will be against it.
H: Teachers’ unions.
A: Local authorities.
H: Educational press.
A:And, of course, the DES. So, what’s the strategy?
H: Well, unions can be counted on to disrupt the schools.
A: And go on TV saying it’s the government who are causing the disruption.
H: Good, yes, and local councils will threaten to turn the constituency parties against the government.
A: Fine, the Department of Education will delay every stage of the process, and leak anything that embarrasses the government. We can help you with that at the Campaign for Freedom of Information.
H: Oh, thank you, Arnold.
A: Ah, thanks.
H: But what are we actually going to do… Thank you, Billy. What’s our argument? A: Well, obviously, this new proposal will destroy our educational system.
H: Well everybody knows it’s destroyed already.
A: Well, we will say… Sorry, the press will say, that it’s government interference in the Department of Education that destroyed it, and this new plan will make things even worse.
H: Will that do the trick?
A: It always has in the past.
H: Yes, but this time the political pressure is stronger.
A: Then you must find a political weapon to fight it with.
H: What political weapon did you have in mind, Arnold?
A: I? That is your concern, Humphrey. Your chance to prove yourself worthy of the high office to which you’ve been called.
B: Well, Sir Humphrey. The PM’s ready to see you.
H: What’s it about.
B: The abolition of the DES, I’m afraid so.
H: This is going to be bloody.
B:Oh, yes. Just before you going, there’s a one another minor matter I need your advice…
H: Is it important, Bernard?
B: Well, it’s not important but it’s urgent.
H: What is it?
B: Well, you know that enterprise school the PM visited…
H: Yes, yes.
B: When they gave him that stool?
H: The stool, yes.
B: Well, it’s just come to light that the wood they were using was stolen.
H: Bernard, this is hardly… Stolen?
B: Yes, it was government property stolen from one of the YTS workshop from pupils who was working at last year.
H: How shocking.
B: Well, it was inferred to the DES employment, because the theft came to light at a school. They don’t know whether to prosecute. I’m, I’m sorry to bother you with this…
H: Don’t mention it, Bernard. Show me in.
PM:Oh, come in, Humphrey. Come in, come in! Sit down. Only one item on the agenda today, the abolition of the DES.
H: Actually, if there’s only one item, it’s an agendum.
B: I don’t think the PM’s got as far as the second declension.
PM:I don’t mind your scoring cheap debating points, since you’ve already lost the battle of the DES.
H: The DES will be very upset, PM.
PM: Does it matter, since they’ll cease to exist?
H: Well, the process will take a year or two. They’ll fight tooth and nail.
PM: What can they do to me?
H: They’re a formidable department.
PM: I am a formidable PM.
H: Indeed you are, PM. But you might still need their cooperation.
PM: Cooperation? From the Department of Education? Don’t make me laugh!
H: Fine, fine. I’ll tell them to go ahead with the prosecution, then.
PM: Prosecution? What prosecution?
H:Oh, it’s hardly worth bothering you with, PM. But that enterprise school where you were televised last week.
PM: Yes?
H: Yes, well, the profits you see… A model for other schools…
PM: Yes, yes, go on.
H: Yes, yes, yes. The profits were apparently the proceeds of theft.
PM: Theft? What do you mean theft?
H: I mean removing goods without the knowledgeor concerned of the owner…PM: Yes, I know the theft means, Humphrey. What do you mean?
H: Well, the stool that they gave to you was made from wood appropriated from the local YTS workshops.
PM: What do you mean?
H: It was nicked. By two of last year’s pupils.
B: A pair of nickers.
H:Thank you, Bernard. Well, the YTS want to prosecute. Now, the Department of Education could stop them. You know, return the wood and hush it up.
PM: Humphrey, millions of people saw me on TV saying that school was an example to Britain!
H: Well, it is a sort of example.
PM: Humphrey, they mustn’t prosecute!
H:Well, I do hope the Department of Education won’t leak the fact that you’re covering up for crooks.
PM: You must tell them not to prosecute.
H:Well, that would need their cooperation. I can just see the newspaper “Jim’s enterprising crooks”, “The PM has sat on the fence for so long that now he’s become one.”
PM: You must persuade them not to prosecute.
H: Well, it’s very difficult to persuade people to cooperate if they are actually under a death sentence.
PM: Death sentence?
H: If you’re thinking of abolishing the department.
PM:Oh, oh, that! No, that was just…a vague idea…of Dorothy’s. An idle thought.
Nothing serious.
H: You’re sure?
PM: Positive.
H: That’s splendid, PM. Shall we now continue with agendum?
PM: Agendum? Oh, yes! We have no agendum.
B: We have no agendum today!
PM: Business concluded. Alright, Humphrey?
H:Yes, PM.
位移传感器原理与分类
位移传感器原理与分类 传感器之家中将位移传感器分为线位移跟物位移两类，这是按照位移的特征分的。位移传感器就是测量空间中距离的大小，线位移就是在一条线上移动的长度，角位移就是转动的角度。下面就线位移做下介绍，线位移按原理分主要有电阻式、电容式、电感式、变压器式、电涡流式、激光式等等。前面三种主要用来测量小位移，中位移一般则用变压器式，大的位移则用电位器式的比较多，对于精密的场合，则需要选择激光式。 电容式位移传感器是把位移的变化换作电容的变化进行制作的。对于振动频率很高的环境条件下，最适合选用这种类型的传感器。它具有灵敏度高、能实现非接触量的测量，而且可以在恶劣场合下工作。它也有一些缺点，比如对连接线缆有很高的要求，它要有屏蔽性能；而且最好选用高频电源用来供电。现在做的最好的电容式位移传感器可以测量0.001微米的位移，误差非常小。 电感式位移传感器是将测量量换作互感的变化的传感器，它既可以测量角位移也可以测量线位移。目前常用到的电感式位移传感器有气隙式，面积式，螺管式三种。变气隙型中电感的变化与传感器中活动衔铁的位移相对应。变面积型是用铁芯与衔铁之间重合面积的变化来反映位移。螺管型是衔铁插入长度的变化导致电感变化的原理。
变压器式位移传感器是用途最广的一种位移传感器，线圈中感应电动势随着位移的变化而变化。这种传感器它的灵敏度都很高，有时都不用放大器。缺点在于质量一般比较大，不应用于高频场合。 电涡流式位移传感器是基于电涡流效应，它的感应参数是阻抗的变化，尽量使阻抗是位移的函数，它还与被测物体的形状跟尺寸有关。该传感器的量程一般在0到80毫米。 电阻式位移传感器是通过测量变化的电阻值来计算位移的变化，它通常分为电位器式跟应变式。前面一种适合测量位移大、精度要求不高的场合；后面一种是利用电阻应变效应，它具有线性度跟分辨率都比较高，失真小的优点。
位移传感器的性能参数与使用方法.
位移传感器的性能参数 标称阻值：电位器上面所标示的阻值。 允许误差：标称阻值与实际阻值的差值跟标称阻值之比的百分数称阻值偏差，它表示电位器的精度。允许误差一般只要在±20%以内就符合要求，因为一般位移传感器是以分压的方式来使用，具体电阻的大小对传感器的数据采集没有影响。 线性精度：直线性误差。此参数越小越好。 寿命：导电塑料位移传感器都在200万次以上。 重复精度：此参数越小越好。 分辨率：位移传感器所能反馈的最小位移数值。此参数越小越好。导电塑料位移传感器分辨率为无穷小。 位移传感器的使用方法 一般采用给位移传感器加上一个电压，利用其优良的平滑性，来检测输出电压（输出电阻改变输出电压）分压比。小编通过搜集整理，以直线位移传感器及磁致伸缩位移传感器为例，简单的分析了位移传感器的使用方法。 （1）直线位移传感器的使用： 美国tom公司生产的精密直线位移传感器，是带有一个长的持续传导轨迹分压计型传感器，在控制和测量运用中，适合于绝对位移传感，其线性精度为士0.05%。具有移动快，寿命长等特点，符合龙门式精密油压机的控制要求。 根据实际要求在油压机的主缸、液压垫上分别安装kl下滑板式、ktc拉杆式直线位移传感器。在一个半自动工作过程中，油压机的主缸、液压垫分别带动两只直线位移传感器移动，将采集到的两点模拟量值输入到fx2n-8ad，fx2n-8ad 将此模拟输入数值（此时是电压输入），转换成数字值，并且把他们传输到plc 主单元。主缸、液压垫选用直线位移传感器的有效测量长度为500mm、400mm。 （2）磁致伸缩位移传感器使用中的注意事项： 磁致伸缩位移（液位）传感器，通过内部非接触式的测控技术精确地检测活动磁环的绝对位置来测量被检测产品的实际位移值的;该传感器的高精度和高可靠性已被广泛应用于成千上万的实际案例中 根据供应商提供的资料，强调了本传感器在使用中必须注意的一些事项，除了上面所介绍的接线方面之外，在与液压油缸的装配中也有一些需要注意的问题：
位移传感器的主要分类
位移传感器的主要分类 根据运动方式 直线位移传感器： 直线位移传感器的功能在于把直线机械位移量转换成电信号。 为了达到这一效果，通常将可变电阻滑轨定置在传感器的固定部位，通过滑片在滑轨上的位移来测量不同的阻值。传感器滑轨连接稳态直流电压，允许流过微安培的小电流，滑片和始端之间的电压，与滑片移动的长度成正比。将传感器用作分压器可最大限度降低对滑轨总阻值精确性的要求，因为由温度变化引起的阻值变化不会影响到测量结果。 角度位移传感器： 角度位移传感器应用于障碍处理：使用角度传感器来控制你的轮子可以间接的发现障碍物。原理非常简单：如果马达角度传感器构造运转，而齿轮不转，说明你的机器已经被障碍物给挡住了。此技术使用起来非常简单，而且非常有效；唯一要求就是运动的轮子不能在地板上打滑（或者说打滑次数太多），否则你将无法检测到障碍物。一个空转的齿轮连接到马达上就可以避免这个问题，这个轮子不是由马达驱动而是通过装置的运动带动它：在驱动轮旋转的过程中，如果惰轮停止了，说明你碰到障碍物了。 根据材质 电位器式位移传感器：它通过电位器元件将机械位移转换成与之成线性或任意函数关系的电阻或电压输出。普通直线电位器和圆形电位器都可分别用作直线位移和角位移传感器。但是，为实现测量位移目的而设计的电位器，要求在位移变化和电阻变化之间有一个确定关系。图1中的电位器式位移传感器的可动电刷与被测物体相连。物体的位移引起电位器移动端的电阻变化。阻值的变化量反映了位移的量值，阻值的增加还是减小则表明了位移的方向。通常在电位器上通以电源电压，以把电阻变化转换为电压输出。线绕式电位器由于其电刷移动时电阻以匝电阻为阶梯而变化，其输出特性亦呈阶梯形。如果这种位移传感器在伺服系统中用作位移反馈元件，则过大的阶跃电压会引起系统振荡。因此在电位器的制作中应尽量减小每匝的电阻值。电位器式传感器的另一个主要缺点是易磨损。它的优点是：结构简单，输出信号大，使用方便，价格低廉。 霍耳式位移传感器：它的测量原理是保持霍耳元件（见半导体磁敏元件）的激励电流不变，并使其在一个梯度均匀的磁场中移动，则所移动的位移正比于输出的霍耳电势。磁场梯度越大，灵敏度越高；梯度变化越均匀，霍耳电势与位移的关系越接近于线性。图2中是三种产生梯度磁场的磁系统：a系统的线性范围窄，位移Z=0时，霍耳电势≠0；b系统当Z<2毫米时具有良好的线性，Z=0时，霍耳电势=0；c系统的灵敏度高，测量范围小于1毫
实验样品采集运输保存方法
1.R N A实验样品采集、保存方法 使用范围及样品量 类别：Microarray Service；Sequencing Service; PCR Array& PCR Service 样本量： 样本样本量 哺乳动物培养细胞样品（悬浮细胞）1*107个 哺乳动物培养细胞样品（贴壁细胞）15cm2 植物组织样品100mg-1g，根据植物不同部位的组织决定组 织需要量，尽可能多些，但不必超过1g 动物组织样品 新鲜组织样品 A. 使用RNAlater试剂 取新鲜组织（注：动物死亡后尽快在10min内取材），组织块以PBS或生理盐水清洗干净，所用组织必须切至厚度在一下，然后放入装有5倍体积RNAlater的离心管（或冻存管）中。 4度孵育过夜，此时样品管需要横置以便组织块充分接触到RNAlater，然后转入-20中保存，样品在-20不会冻结，但溶液中可能会有一些晶体出现，这并不影响后续的RNA抽提。 B. 使用Trizol试剂 取新鲜组织（1min以内），组织块以PBS或生理盐水清洗干净，每50-100mg组织加入1ml Trizol溶液匀浆裂解组织样品，最好冰上进行操作。
匀浆的裂解液4度短期保存（1month），-20或者-70度长期保存。 冻存组织 生物体死亡后尽快（10min以内）切取新鲜组织，并以PBS或生理盐水清洗干净切成小块；培养液倒入离心管中，离心沉淀细胞，弃去上清液。 细胞沉淀（1*107个）中加入1ml Trizol裂解液 反复吸打几次后，目视可见细胞层溶液完全 -70保存 贴壁细胞 从培养容器中吸出并弃去培养液 培养瓶直接加入Trizol试剂，Trizol用量与细胞贴壁面积有关，15cm2细胞贴壁面积加入1mlTrizol。 反复吸打几次后，目视可见细胞层溶解完全。 -70度保存。 植物组织样品 准确取得所需新鲜组织后，如有必要可用PBS清洗干净，将所用组织切碎，装入冻存管中或者用锡箔包裹好。 立即投入液氮中保存。 2.血液类样品采集、保存方法 适用范围及样品量 全血/血细胞：Microarray Service；Sequencing Service; PCR Array& PCR Service 血清/血浆：Microarray Service；PCR Array& PCR Service
位移传感器应用在哪些领域
众所周知，位移传感器是将感应到的电信号转换成信息传出，供人们了解位移距离的元件，由于其类型不同，所应用的领域也存在差异。 常用的有应变式位移传感器，磁致伸缩位移传感器，光栅位移传感器，激光位移传感器，角度位移传感器等。 磁致伸缩位移传感器的应用 注塑机、压铸机、吹瓶机、液压机、鞋机、橡胶机、轮胎硫化机、压延机、五金机械（监控模具厚度变化和平衡）、钢厂轧辊调节、盾构机、液压伺服系统、液位检测和控制。 激光位移传感器的应用 激光传感器常用于长度、距离、振动、速度、方位等物理量的测量，还可用于探伤和大气污染物的监测等。 角度位移传感器的应用 地理: 山体滑坡，雪崩 民用: 大坝，建筑，桥梁，玩具，报警，运输 工业：吊车，吊架，收割机，起重机，称重系统的倾斜补偿，沥青机.铺路机等 火车：高速列车转向架和客车车厢的倾斜测量 海事：纵倾和横滚控制，油轮控制，天线位置控制 钻井：精确钻井倾斜控制 机械：倾斜控制，大型机械对准控制，弯曲控制，起重机
军用：火炮和雷达调整，初始位置控制，导航系统，军用着陆平台控制 直线位移传感器（电子尺）的应用领域 注塑机、压铸机、吹瓶机、液压机、鞋机、砖机、砌垛机、陶瓷机械、列车轨距监测、橡胶机、轮胎硫化机、压延机、五金机械（监控模具厚度变化和平衡）、皮革机械、比例阀、长行程钻管机、弹簧机械、木工机械、板材设备、印刷机械（刷辊运动、裁纸等）、钢厂轧辊调节、机械手、自动门（列车及大厅）、裁床（裁钢管、木板、线材等）、桥梁监测、煤炭设备（掘进机、坑道支架、塌方监测等）、地质监测（如：塌方、溃堤）。 拉绳/拉线位移传感器的应用领域 舞台屏幕设备、皮革机械、盾构机、长行程钻管机、弹簧机械、木工机械、板材设备、印刷机械（刷辊运动、裁纸等）、机械手、自动门（列车及大厅）、裁床（裁钢管、木板、线材等）、桥梁监测、电梯平层、升降机、水闸开度、水库水位、行车、工程车、龙门吊、港口设备、煤炭设备（掘进机、坑道支架、塌方监测等）、水处理液位、仓储设备、地质监测（如：塌方、溃堤）、石油钻探设备、探矿设备等。 以上就是相关内容的介绍，希望对大家了解这一问题会有更多的帮助，同时如有这方面的兴趣或需求，可以咨询了解一下南京凯基特电气有限公司。
位移传感器常见故障之如何解决【干货】
位移传感器常见故障是什么？ 内容来源网络，由“深圳机械展（11万㎡，1100多家展商，超10万观众）”收集整理！ 更多cnc加工中心、车铣磨钻床、线切割、数控刀具工具、工业机器人、非标自动化、数字化无人工厂、精密测量、3D打印、激光切割、钣金冲压折弯、精密零件加工等展示，就在深圳机械展. 直线的工作原理是跟滑动变阻器一样的，它作为分压器使用的，它是以相对的输出电压来呈现出所测量位置的实际上的位置。对这个装置的工作有下面几点要求： 1、如果电子尺已经使用很长时间了，而且密封已经老化，同时夹杂着很多杂质，而且水混合物和油会严重影响电刷的接触电阻的，这样会使显示的数字不停地跳动。这个时候可以说直线位移传感器的电子尺已经损坏了，需要更换。 2、若电源的容量很小，就会出现很多情况的，所以，供电电源需要有充分的容量。那么，容量不足，就会造成如下的情况：熔胶的运动会使合模电子尺的显示变换，有波动，或者合模的运动会使射胶电子尺的显示波动，造成测量结果误差很大。如果电磁阀的驱动电源于直线位移传感器供电电源同时在一起的时候，更容易出现以上的情况，情况严重时用万用表的电压档甚至可以测量到电压的有关波动。如果情况不是因为高频干扰、静电干扰或者是中性不够好的造成的，那么就有可能是电源的功率太小造成的。 3、调频干扰和静电干扰都有可能让直线位移传感器的电子尺的显示数字跳动的。电子尺的信号线与设备的强电线路要分开线槽。电子尺必须要强制性地使用接地支架，而且同时让电子尺的外壳跟地面良好地接触。信号线需要使用屏蔽线，而且电箱的一段应该跟屏蔽线接地的。 如果有高频干扰的时候，通常使用万用表的电压测量就会显示正常，但是显示数字就是会跳动不停的；而出现静电干扰时，出现的情况也是跟高频干扰一样的。要证明看是否是静电干扰时，可以先使用一段电源线把电子尺的封盖螺丝跟机器上的某一些的金属短接起来就可以了，只要一短接起来，静电干扰就会马上消除掉的。但是如果要消除掉高频干扰就很难用上面的方法了，变频节电器和机器手都经常出现高频干扰的，所以可以试一下用停止高频节电器或者机械手的方法来验证是不是高频干扰的。
直线位移传感器常见使用问题
直线位移传感器常见问题 问题一：传感器供电电源容量小 供电电源容量不足，就会造成以下的情况：熔胶的运动会使合模电子尺的显示变换，有波动，或者合模的运动会使射胶电子尺的显示波动，造成测量误差变大。如果电磁阀的驱动电源与直线位移传感器供电电源共用的时候，更容易出现这种情况。 问题二、调频干扰和静电干扰 调频干扰和静电干扰都有可能让直线位移传感器的电子尺的显示数字跳动的。所以，电子尺的信号线与设备的强电线路要分开线槽。电子尺必须强制性地接地。信号线需要使用屏蔽线，而且电箱的一段应该跟屏蔽线接地的。如果有高频干扰的时候，通常使用万用表的电压测量就会显示正常，但是显示数字就是会跳动不停的；而出现静电干扰时，出现的情况也是跟高频干扰一样的。要证明看是否是静电干扰时，只需用一段电源线把电子尺的封盖螺丝跟机器上的某一些的金属短接起来就可以了，只要一短接起来，静电干扰就会马上消除掉。但是如果要消除掉高频干扰就很难用上面的方法了，直链淀粉检测仪可以试下暂停高频干扰源，看显示结果会不会更好，以此来判断是不是高频干扰的问题。 问题三、显示数据有规律地跳动，或者是没有显示数据 出现这种情况就需要检查连接线绝缘是不是出现破损的现象，并且跟机器的外壳很有规律地接触而导致的对地短路。 问题四、传感器的对中性、平行度以及角度有那些要求 安装直线位移传感器的对中性需要很好，但是平行度可以允许有±0.5mm的误差，角度可以允许有±12°的误差。但是如果平行度误差和角度误差都是偏大的话，这样会出现显示数字跳动的情况。粘度测定仪那么出现这样的情况的时候，必须要对平行度和角度进行调整了。 问题五、传感器接线错误 直线位移传感器的三条线是不可以接错的，电源线和输出线是不可以调换的。如果上面的线接错的话，就会出现线性误差很大的情况，要控制的话是很难的，控制的精度也会变得很差，而显示很容易出现跳动的现象等等。 以上回答仅供参考。
位移传感器的主要应用领域
直线位移传感器（电子尺）的应用领域 注塑机、压铸机、吹瓶机、液压机、鞋机、砖机、砌垛机、陶瓷机械、列车轨距监测、橡胶机、轮胎硫化机、压延机、五金机械（监控模具厚度变化和平衡）、皮革机械、比例阀、长行程钻管机、弹簧机械、木工机械、板材设备、印刷机械（刷辊运动、裁纸等）、钢厂轧辊调节、机械手、自动门（列车及大厅）、裁床（裁钢管、木板、线材等）、桥梁监测、煤炭设备（掘进机、坑道支架、塌方监测等）、地质监测（如：塌方、溃堤）。 拉绳/拉线位移传感器的应用领域 舞台屏幕设备、皮革机械、盾构机、长行程钻管机、弹簧机械、木工机械、板材设备、印刷机械（刷辊运动、裁纸等）、机械手、自动门（列车及大厅）、裁床（裁钢管、木板、线材等）、桥梁监测、电梯平层、升降机、水闸开度、水库水位、行车、工程车、龙门吊、港口设备、煤炭设备（掘进机、坑道支架、塌方监测等）、水处理液位、仓储设备、地质监测（如：塌方、溃堤）、石油钻探设备、探矿设备等。 磁致伸缩位移传感器应用领域 注塑机、压铸机、吹瓶机、液压机、鞋机、橡胶机、轮胎硫化机、压延机、五金机械（监控模具厚度变化和平衡）、钢厂轧辊调节、盾构机、液压伺服系统、液位检测和控制 艾驰商城是国内最专业的MRO工业品网购平台，正品现货、优势价格、迅捷配送，是一站式采购的工业品商城！具有10年工业用品电子商务领域研究，以强大的信息通道建设的优势，以及依托线下贸易交易市场在工业用品行业上游供应链的整合能力，为广大的用户提供了传感器、图尔克传感器、变频器、断路器、继电器、PLC、工控机、仪器仪表、气缸、五金工具、伺服电机、劳保用品等一系列自动化的工控产品。 如需进一步了解图尔克、奥托尼克斯、科瑞、山武、倍加福、邦纳、亚德客、施克等各类传感器的选型，报价，采购，参数，图片，批发信息，请关注艾驰商城https://www.wendangku.net/doc/3714647574.html,/
送检样品正确采集方法简介
送检样品正确采集方法简介 项玉英 （浙江省台州市农业科学研究院检测中心317000） 样品的采集简称采样（又称检样、捡样、取样、抽样等），是为了进行检验而从大量物料中抽取的一定量具有代表性的样品。在实际工作中，要化验的物料常常是大量的，其组成有的比较均匀，有的却很不均匀。化验时所取的分析试样只需几克、几十毫克、甚至更少，而分析结果必须能代表全部物料的平均组成。因此，必须正确地采取具有足够代表性的“平均试样”。若所采集的样品组成没有代表性，那么之后分析再准确也没有用处，甚至可能导致错误的结论，给生产或科研带来很大的损失。 本院检测中心主要承接土壤、水质、肥料和植物等主要成份的系统检测，在多年的检测工作中，发现一些客户在采样上存在采样数量不足、采样点不够多等问题。本文将有针对性地对这几大类物体的采样方法作一详细说明。 1土壤样品的采集 1.1土壤样品的采集原则 土壤采样是土壤分析工作的一个重要环节，是关系到分析结果和由此得出的结论是否正确的一个先决条3.2春玉米 品种：选择苏玉1号和苏玉糯为主栽品种。栽培要点：早春保湿育苗，2月下旬播种，小拱棚育苗、露地栽培播种时间为3月下旬，在适期范围早播，产量高，经济效益好。但早播时间应在土壤10cm 、土温稳定在10~12℃以上方可播种。本地常规年份在3月20日左右，叶龄在3叶1心时可移栽；生产上要抓好壮苗、攻穗两大环节，重施基肥和攻蒲肥；肥料施用比例按对半分或四、六开两次施入，施肥量为每667m 2施有机肥500~1000kg ，无机肥纯氮15kg 、P 2O 56kg 、K 2O 6kg 。肥力较好的田块可适当减少。有机肥磷、钾肥作基肥一次性施入。田间管理重点抓好苗期的地下害虫，前、中期杂草和中、后期的螟虫防治。防鼠及地下害虫在移栽时用菜饼拌800倍敌百虫诱杀，除草害可用90%耐斯300ml 兑水喷洒，在玉米喇叭口展现期用杀螟松1000倍溶液或50%敌敌畏乳油800~1000倍液灌雄穗防治螟虫，用10%一遍净粉剂2500~3000倍液喷雾防治蚜虫。 3.3夏玉米 6月下旬直播，8月下旬至9月下旬收获。田间管理重点抓好蚜虫和玉米螟虫防治，防治方法同春玉米相同，防治玉米螟也可在喇叭口时用5%锐劲特悬浮剂2000~3000倍灌心防治。 3.4秋马铃薯 8月中下旬播种，11月中下旬收获，播种方式和施肥量与春马铃薯露地一样。 4小结 山区旱地一年四熟高效农业的实践，深受山区群众的欢迎，并取得了较好经济效益，为挖掘山区旱地的内在的潜力，调整农业结构，发展效益农业奠定了基础。 收稿日期：2004.12.24 台州农业2006，（1）：21～23 Journal of Taizhou Agriculture
位移传感器的安装方法
位移传感器的功能是将机械的位移量转换成电信号，在我们选择位移传感器的时候需要考虑的有安装方式线性精度和供电情况，同样需要知道你的大概测量范围去选择更加合适的位移传感器。 首先我们在选择位移传感器规格范围时需留有余量，一般情况下最好是在实际行程的基础上选大一规格的即可。同样还需要注意的是你选择的是电涡流位移传感器，拉线位移传感器还是滑块位移传感器。如果你的位移传感器不便于进行对中调整的场合使用的话，最好是使用滑块位移传感器。而就位移的量程而言，大量程的建议使用的拉线位移传感器，电涡流位移传感器只是相对精度比较高的去测量。滑块位移传感器可以减少调整对中性的工作量，但辅助加长杆不能取消，否则，会出现由于对中性不好而导致稳定性和使用寿命，所以类似的位移传感器安装要是相当严格的。 位移传感器的安装要求根据你测量的是振动和位移，如果是轴的径向振动测量就得要求轴的直径大于探头直径的三倍以上。每个测点应同时安装两个传感器探头，两个探头应分别安装在轴承两边的同一平面上相隔90度。轴的径向振动测量时探头的安装位置应该尽量靠近轴承。探头中心线应与轴心线正交，探头监测的表面必须是无裂痕或其它任何不连续的表面现象。 如果是轴的轴向位移测量测量面应该与轴是一个整体，这个测量面是以探头的中心线为中心，宽度为1.5倍的探头圆环。探头安装距离距止推法兰盘不应超过305mm，否则测量结果不仅包含轴向位移的变化，而且包含胀差在内的变化，这样测量的不是轴的真实位移值。对于位移传感器的测量方式不一样，对应的安装就需要有不一样的要求。 艾驰商城是国内最专业的MRO工业品网购平台，正品现货、优势价格、迅捷配送，是一站式采购的工业品商城！具有10年工业用品电子商务领域研究，以强大的信息通道建设的优势，以及依托线下贸易交易市场在工业用品行业上游供应链的整合能力，为广大的用户提供了传感器、图尔克传感器、变频器、断路器、继电器、PLC、工控机、仪器仪表、气缸、五金工具、伺服电机、劳保用品等一系列自动化的工控产品。 如需进一步了解相关传感器产品的选型，报价，采购，参数，图片，批发等信息，请关注艾驰商城https://www.wendangku.net/doc/3714647574.html,。
样品的采集方法
2 样品的采集 2. 1 采样时间和采样深度对桉树土壤中微量元素分布规律的分析,是为了从微量元素的角度,探讨 桉树土壤的特征性。 桉树土壤中微量元素的含量,与样品的采集时间和采样深度相关。由于不同时间采集的土壤样品与残 留在土壤中微量元素含量大小的数据是不一样的。桉树土壤样品的采样时间,可在砍伐后或施肥前,一般在秋冬季至早春采样较为合适。桉树的根系分布比较深,为了探讨围绕根系的微量元素分布,依据桉树根系的深度,采样深度一般定为0~40cm。 2. 2 采样点数及分布每一个桉树土壤样品采样点的分析结果,代表一个采样单元面积的桉树土壤状况。如果所设定的采样点没有代表性,即使分析结果再准确也无实用价值。因此必须科学设定采样点,并在采样单元中多点采样,然后以多点采集样品的均匀混合样作为采样单元的代表点。采样点数的多少,根据地形地貌、不同的桉树品种和采样单元的大小来确定。可用梅花形和蛇形(S形)等两种布点方法采样。采样单元面积较小,地势平坦,可用梅花形布点采样,中心点设在两对角线相交处,设5个采样点(见图a所示); 采样单元面积较大,地势不平坦,可用蛇形(S形)布点采样,按“S”形的路线均匀分布5~10个采样点[2]。采样点要避开林边、路边、河边和堆肥处等特殊部位。 2. 3 采样每点采样时,首先挖土坑,土坑一般挖成1×1. 5米的长方形[2],挖出的土壤放在土坑两侧, 土坑深度依具体情况而定,分析微量元素含量一般应挖至50cm。根据土壤剖面的颜色、结构、质地、松紧度、湿度、桉树根系分布等,自上而下划分土层,进行仔细观察,描述记载,将剖面形态特征逐一记载到采样记录表。然后,把每一个采样点的采样深度分为3层: 0~10cm、10~20cm、20~40cm。采样次序自下而上逐层采样,通常采集各层中部位置的土壤,而不是整层都采。先采剖面的底层土样(20~40cm),再采中层土样(10 ~20cm),最后采上层土样(0~10cm)。将所采集的三层土样分别放入相应的样品袋,用铅笔写好样品标签,每个样品须写2个同样标签,并贴在样品袋的内外两侧。标签内容包括编号、桉树品种、采样地点、采样深度、采样人、采样时间等。一般每一层采集1 kg左右的样品。在采样过程中要注意用竹片去除与铁锹和铁铲等金属器具接触的部分土壤,再用竹片取样,避免在采样中引入微量元素的干扰。 2. 4 采样时进行野外记录采样时进行野外记录,是一项必不可少的工作。其作用是为研究桉树土壤 微量元素含量的变化规律提供依据。野外记录的项目有:桉树品种、种植年代、生产情况、胸径、林下植被生长状况、坡向、坡度。采样地是否刚施过肥、下过雨,天气状况。 3 样品的预处理 采集回来的桉树土壤样品,经登记编号后,都须经过一定的预处理。风干、磨细、过筛、混合、制成分析样品保存,进行各项分析。预处理样品的目的是: ①使分析样品可以长期地保存,不致因微生物活动而变质;②挑去非去部分,使分析结果能代表土壤本 身组成;③将样品适当磨细和充分混匀,使分析时所取的样品具有较高的代表性,减少称样的误差;④将样品
对位移传感器的认识
对位移传感器的认识 桥梁试验是指应用测试手段，对桥梁结构的整体或主要部件进行检测,了解桥梁结构及其部件的工作状态和承载能力,以验证桥梁结构的设计计算理论，检验施工质量和发现运用中存在的问题等。 桥梁试验用的设备可分为机械式测试仪器，电测仪器和光测仪器三大类。桥梁常使用的机械式测试仪器，主要有应变计、位移计和振动仪等三大类。电测仪器一般由传感器、电子测量仪器（主机）和指示记录装置组成。 一，概述 传感器。根据其测试内容的不同，可分为应变传感器、反力传感器、位移传感器、振动传感器等。根据其转换的原理不同，可分为电阻式传感器、电感式传感器、电容式传感器、磁电式传感器、压电式传感器等。其中电阻应变片是在桥梁电测中应用最广泛的一种传感器，它是利用一些金属丝的电阻随其在长度方向的应变，在一定范围内保持线性关系的原理制成的。为了增大电阻的变化量和减少应变片的长度，通常采用高电阻率的电阻丝绕制成栅状，做成应变片。测试时，把它牢固地粘贴在测点上，当测点处的基材发生应变时，电阻应变片随之发生应变，其电阻值也作相应的改变，这就达到了非电量向电量的转换。电阻应变片不但可以测量应变，而且在加上一些附件之后，可以对位移和振动等进行测量。 位移传感器又称为线性传感器，它分为电感式位移传感器，电容式位移传感器，光电式位移传感器，位移传感器超声波式位移传感器，霍尔式位移传感器。电感式位移传感器是一种属于金属感应的线性器件，接通电源后，在开关的感应面将产生一个交变磁场，当金属物体接近此感应面时，金属中则产生涡流而吸取了振荡器的能量，使振荡器输出幅度线性衰减，然后根据衰减量的变化来完成无接触检测物体的目的。 二，各种传感器的特点 电感式位移传感器具有无滑动触点，工作时不受灰尘等非金属因素的影响，并且低功耗，长寿命，可使用在各种恶劣条件下。位移传感器主要应用在自动化装备生产线对模拟量的智能控制。 光电式位移传感器利用激光三角反射法进行测量，对被测物体材质没有任何要求，主要影响为环境光强和被测面是否平整。比如公路测量用到真尚有的激光位移传感器，就对传感器进行了特殊配置，与普通情况不一样。 位移是和物体的位置在运动过程中的移动有关的量，位移的测量方式所涉及的范围是相当广泛的。小位移通常用应变式、电感式、差动变压器式、涡流式、霍尔传感器来检测，大的位移常用感应同步器、光栅、容栅、磁栅等传感技术来测量。其中光栅传感器因具有易实现数字化、精度高（目前分辨率最高的可达到纳米级）、抗干扰能力强、没有人为读数误差、安装方便、使用可靠等优点，在机床加工、检测仪表等行业中得到日益广泛的应用。 三，辨向原理 在实际应用中，位移具有两个方向，即选定一个方向后，位移有正负之分，因此用一个光电元件测定莫尔条纹信号确定不了位移方向。为了辨向，需要有π/2相位差的两个莫尔条纹信号。如图2，在相距1/4条纹间距的位置上安放两个光电元件，得到两个相位差π/2的电信号u01和u02，经过整形后得到两个方
位移传感器-矿用位移传感器使用说明书
GUD1200 矿用本安型位移传感器产品使用说明书 2013年1月5日
目录 1. 概述 (3) 1.1 主要用途及使用范围 (3) 1.2 型号组成及代表意义 (3) 1.3 使用环境条件 (3) 2 结构特征与工作原理 (3) 2.1 结构 (4) 2.2 工作原理 (4) 3 技术特性 (4) 3.1 产品执行标准 (4) 3.2 主要性能 (4) 3.3 主要参数 (4) 3.4尺寸重量 (4) 3.4.1 尺寸 (4) 3.4.2 重量 (4) 4 安装、调试 (4) 4.1 安装条件、技术要求 (4) 5 使用、操作 (5) 6 故障分析与排除 (5) 7 注意事项 (5) 8 运输、贮存 (6) 9 开箱及检查 (6) 10 订货 (6)
使用本产品前，请详细阅读本说明书。 GUD1200矿用本安型位移传感器 1.概述 1.1主要用途及使用范围 矿用本安型位移传感器主要用于煤矿采煤工作面液压支架位移量的测量，其工作简单可靠，能够直观显示位置信号，避免常规的电器产品中电气电路经常出现问题的弊端。 传感器内部为干簧管及电阻，属简单设备。传感器防爆型式为矿用本安型，防爆标志：“Exib I”。 1.2型号组成及代表意义 1.3使用环境条件 ——环境温度－5℃～40℃； ——海拔高度不超过2000m； ——空气相对湿度不大于95％（25℃时）； ——在有瓦斯、煤尘爆炸危险的场所； ——在无破坏绝缘的腐蚀性气体或蒸汽的场所； ——在无显著振动和冲击的场所； ——污染等级为3级； ——安装类别为Ⅲ类。 2结构特征与工作原理
2.1结构 图1 结构图 2.2工作原理 指示环固定在液压支架上，当液压支架位移发生变化时带动指示环前后动作，指示环上封装有磁铁，在传感器杆体每0.05m处分别装有干黄管，当磁铁接近干簧管时，导致干簧管接通。 3技术特性 3.1产品执行标准 本产品执行标准GB3836-2010、Q/0104ZMD047—2013。 3.2主要性能 --输入电压：DC12V； 3.3主要参数 3.3.1 电压：DC12V； 3.3.2 接点容量：12V/1A。 3.4尺寸重量 尺寸: φ30mm×1225mm ,重量: 约3kg。 3安装、调试 4.1安装条件、技术要求 4.1.1在安装前，请详细检查产品是否损坏，检查接入电压是否与本说明书一致。
位移传感器的应用
利用传感器进行位移的测量 【摘要】：位移传感器是新技术革命和信息社会的重要技术基础，传感器技术是实现测试与自动控制的重要环节。主要介绍磁致伸缩位移传感；激光位移传感器；电阻应变片式位移传感器的测量位移的应用。磁致伸缩位移（液位）传感器，是利用磁致伸缩原理，通过两个不同磁场相交产生一个应变脉冲信号来准确地测量位置的；激光发射器通过镜头将可见红色激光射向被测物体，当物体沿激光线方向发生移动时，测量结果就将发生改变，从而实现用激光测量物体的位移；电阻应变式位移传感器测量位移，当被测对象作用产生位移x时，应变片的阻值随之产生变化。然后通过测量电路将应变片电阻值变化转化成电压或电流等易测量输出，根据测得的电压或电流值就可以得出应变片电阻值的变化量，再根据应变片阻值的变化量与悬梁产生的位移之间的对应关系，即可得出悬臂梁位移x的大小。 【关键词】：传感器；位移传感器；磁致伸缩位移传感；激光位移传感器；电阻应变片式位移传感器
Using sensors for displacement measurement 【 abstract 】 displacement sensor is a new technology revolution and the information society's important technology base, sensor technology is to achieve test and automatic control important segment. Mainly introduces magnetostrictive displacement sensing; Laser displacement sensor; Resistance strain chip displacement sensor measuring displacements of applications. Magnetostrictive displacement (level) sensor, which USES a magnetostrictive principle, through two different magnetic field fellowship produce a strain pulse signal to accurately measure the position; Laser emitter red laser will be visible through a lens into object to be tested, when objects move along the direction of laser line, the measured results occur when it will change, so as to realize the displacement with laser measuring objects; Resistance strain type displacement sensor measurement of displacement, when tested object effects from the strain gauge shift, generates resistance of change. Then through the measurement circuit will strain film electrical resistance changes into voltage or current, according to wait for easy measurement output voltage or current measurement of the strain gauge shows the amount of variation resistance strain gauge, again according to the variation of without resistance with the displacement produced the corresponding relationship between displacement, can draw the size of the cantilever beam. 【 key words 】 sensors; Displace ment sensor; Magnetostrictive displacement sensing; Laser displacement sensor; Resistance strain chip displacement sensor
位移传感器
位移传感器 一、简介 位移传感器又称为线性传感器，是一种属于金属感应的线性器件，传感器的作用是把各种被测物理量转换为电量。在生产过程中，位移的测量一般分为测量实物尺寸和机械位移两种。按被测变量变换的形式不同，位移传感器可分为模拟式和数字式两种。模拟式又可分为物性型和结构型两种。常用位移传感器以模拟式结构型居多，包括电位器式位移传感器、电感式位移传感器、自整角机、电容式位移传感器、电涡流式位移传感器、霍尔式位移传感器等。数字式位移传感器的一个重要优点是便于将信号直接送入计算机系统。这种传感器发展迅速，应用日益广泛。位移是和物体的位置在运动过程中的移动有关的量，位移的测量方式所涉及的范围是相当广泛的。小位移通常用应变式、电感式、差动变压器式、涡流式、霍尔传感器来检测，大的位移常用感应同步器、光栅、容栅、磁栅等传感技术来测量。其中光栅传感器因具有易实现数字化、精度高（目前分辨率最高的可达到纳米级）、抗干扰能力强、没有人为读数误差、安装方便、使用可靠等优点，在机床加工、检测仪表等行业中得到日益广泛的应用。 二、工作原理 电位器式位移传感器，它通过电位器元件将机械位移转换成与之成线性或任意函数关系的电阻或电压输出。普通直线电位器和圆形电位器都可分别用作直线位移和角位移传感器。但是，为实现测量位移目的而设计的电位器，要求在位移变化和电阻变化之间有一个确定关系。电位器式位移传感器的可动电刷与被测物体相连。 物体的位移引起电位器移动端的电阻变化。阻值的变化量反映了位移的量值，阻值的增加还是减小则表明了位移的方向。通常在电位器上通以电源电压，以把电阻变化转换为电压输出。线绕式电位器由于其电刷移动时电阻以匝电阻为阶梯而变化，其输出特性亦呈阶梯形。如果这种位移传感器在伺服系统中用作位移反馈元件，则过大的阶跃电压会引起系统振荡。因此在电位器的制作中应尽量减小每匝的电阻值。电位器式传感器的另一个主要缺点是易磨损。它的优点是：结构简单，输出信号大，使用方便，价格低廉。
样品的采集及注意事项
样品的采集及注意事项 一、采样前准备工作 1、文件类：委托书、文件、抽样目录； 2、现场用品：抽样员证、三种表格、公章、印泥、所用类目抽样细则单独列出； 3、办公设备：电脑、打印机、插线板、白纸； 4、其他：抽样号、封签、现金。 二、与当地食药部门沟通 出示委托书、文件、抽样目录。 嘉峪关：市场监督管理局510，联系人：何科长、李科长； 酒泉：市局综合科谢科长、李科长出函，再去相应县（市、区）局沟通； 三、样品的采集 概念：从大量的分析对象中抽取具有代表性的一部分样品作为分析化验样品，这项工作即称为样品的采集或采样。 遵循的原则：第一，采集的样品要均匀一致，有代表性，能够反映被分析食品的整体组成、质量和卫生状况；第二，在采样过程中，要设法保持原有的理化指标，防止成分逸散或带入杂质。 1、抽样前向负责人出示抽样员证，并索要其单位营业执照及许可证； - 1 -
2、抽样时注意所选物品生产许可证中间4位是否与所抽类目要求一致，按照细则要求抽取相应数量，散装食品根据比例分成检验和留样两包。还要注意生产日期与保质期，临近过期的物品不应抽取，应至少有三个月的有效期。抽取的样品应是同一批次； 3、分类并贴抽样号，每种预留一个抽样号； 4、电脑系统登记、打出抽样单，签字、盖公章。注意登记清楚被抽样单位信息和样品信息； 5、填写三类表格，填好盖章后，请被抽样单位负责人分别在表格、抽样单及封样签相应位置签名盖章，无公章可按手印。 6、封样。将每种样品分成检验和留样两包，比例基本为2:1，在留样外包装上粘贴前面预留的抽样号，并在封口处粘贴封样签。 7、拍照。货架、营业执照、许可证以及负责人和抽样人员在封好的样品旁进行拍照。 四、样品的保存及运输 易变质食品应尽可能当天寄出，最好提前准备好冰块或冰袋，在每批运送的箱子上做好标记，便于下一步工作的顺利进行。 五、需要注意的事项 1、抽检前须先了解抽取样品的有关规定。每种产品均有其不同的执行标准，不同的产品执行标准，样品抽取的工序和要求 - 2 -
空气样品的采集方法和采样仪器
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够的稳定时间，以满足分析测定所需时间的要求。(3)污染物质被吸收后，应有利于下一步分析测定，最好能直接用于测定。(4)吸收液毒性小、价格低、易于购买，且尽可能回收利用。增大被采气体与吸收液接触面积的有效措施是选用结构适宜的吸收管(瓶)。几种常用吸收管：1、气泡吸收管2、冲击式吸收管3、多孔筛板吸收管(瓶)(二)填充柱阻留法填充柱是用一根长6～l0cm、内径3～5mm的玻璃管或塑料管，内装颗粒状或纤维状填充剂制成。采样时，让气样以一定流速通过填充柱，则欲测组分因吸附、溶解或化学反应等作用被阻留在填充剂上，达到浓缩采样的目的。采样后，通过解吸或溶剂洗脱，使被测组分从填充剂上释放出来进行测定。根护填充剂阻留作用的原理，可分为吸附型、分配型和反应型三种类型。(三)滤料阻留法该方法是将过滤材料(滤纸、滤膜等)放在采样夹上，用抽气装置抽气，则空气中的颗粒物被阻留在过滤材料上，称量过滤材料上富集的颗粒物质量，根据采样体积，即可计算出空气中颗粒物的浓度。(一) 低温冷凝法 (五)静电沉降法 (六)扩散(或渗透)法 (二) (七)自然积集法 (八)综合采样法 三、采样仪器 (一)组成部分空气污染物监测多采用动力采样法，其采样器主要由收集器、流量计和采样动力三部分组成。1、收集器：收
LVDT位移传感器原理及应用—信为科技
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