Instrument-如何使用-有什么中文资料面包板社区

In a previous column , I described how I'd been introduced to Jason Dueck and his colleagues at Instrument Meter Specialties . These guys and gals are experts in anything and everything to do with both antique and modern meters, including repairing and restoring the little beauties. In a moment I'm going to reveal some extremely useful information for anyone interested in using analogue meters -- both for hobby projects and for commercial systems. First, however, a few people have asked me if there is much demand for repairing and restoring these little scamps. Well, my answer is "More than you might think." Let's start with mission-critical facilities like nuclear power stations, some of which were commissioned decades ago. When these facilities are first designed and constructed, they undergo a massive -- and incredibly expensive -- certification process. As time passes and items of equipment start to need servicing or replacing, you can't simply swap things out for replacement parts that are "sort of similar" -- you have to use identical components and subsystems (the alternative is to undergo a time-consuming and eye-wateringly expensive re-certification). Even in the case of less critical industrial complexes, if you have a control room that's been happily working away for the last couple of decades and an analogue meter fails, do you really want to re-engineer things to use more modern components, or would you rather simply refurbish or replace the meter and move on with your life? Suppose you have an antique meter that's sticking. Is it expensive to have it sorted out and recalibrated? Well, it can be a lot less expensive than buying a new one, let me tell you. You have to remember that these are precision pieces of equipment. In their heyday circa the 1940s, 1950s, 1960s, and 1970s when they were all over the place, a good meter could easily cost... well, I don't actually know, but enough to bring tears to your eyes. Suffice it to say that only industrial customers could typically afford to use them. These days, if you want to purchase a perfect reproduction of a classic unit, the price can range as high as $10,000 or more. (Needless to say, this makes the ones one can pick up for around $2 to $5 at flea markets all the more attractive.) As one simple example, Jason was telling me about a meter used in the cockpit of an old cargo plane to indicate the status of the landing gear. These planes are still flying around the world to this day. The meter in question has three positions indicating "Bad" -- "Good" -- Bad." If one of these meters fails -- which they do with increasing regularity as the years go by -- one could theoretically replace it with a relatively cheap functional equivalent. In practice, however, the original unit had the FAA seal of approval, and using anything else would require a time-consuming and expensive recertification. Thus, your alternatives are to pay around $5,000 for a reproduction version of the original meter, or pay a fraction of this to have the original unit refurbished. One of my favorite meters is a 4.5" diameter Phaostron, which is going to be the main focus of my Phrankly Phenomenal Ultra-Macho Prognostication Engine . This was the first meter that started to cause me problems. Since then, a couple of my other meters have started to "throw a wobbly," which is why I'm so happy about running across the folks at Instrument Meter Specialties. The point is that a week or so ago, I discovered the Phaostron company is still in business, so I called them to see if they could help me out. They informed me that they don't have any off-the-shelf units -- these days they build meters "to order" for things like nuclear submarines. We didn't talk price, but if I were a betting man I'd lay odds that they aren't cheap. Of course, in non-mission-critical situations where you are not obliged to use a one-for-one replacement, there are relatively inexpensive modern equivalents available. Jason was telling me that some of these can be obtained for as little as $100 -- the trick is in knowing where to go and what to look for. All of which leads us to... Priceless nuggets of knowledge During one of our conversations, I mentioned to Jason that I had the impression that my Triplet meters, which I really like the look-and-feel of, were a tad more prone to problems than were my Simpsons. Jason explained that the older Simpson meters had larger tolerances than Tripletts, which meant that they were less likely to jam up. On the one hand this would seem like a good thing, but there's always more to this sort of thing than first meets the eye. In a follow-up email to Jason, I told him about our forthcoming EETimes Road Trip to Hamvention, which -- I am informed -- is the largest Hamfest and electronics flea market on the planet. I reminded Jason what he'd said about the Simpsons and Triplets, and asked if he had any other nuggets of knowledge he would care to share. Jason responded as follows: You are correct about the Simpson meters. The Simpson meters are also a much older and less sophisticated design, causing their non-linearity issues. They are also suffering from US suppliers going belly up, resulting in users having a difficult time finding compatible replacements. Simpson may have anywhere from one to five artworks for a given meter depending on the coil alignment with the magnetic field. These artworks are done to save time, fixing variations caused by poor assembly and nearly incompatible parts making the meter linearity even more perfect by compensating for coil placement variations. This has led to a slow decline in the once proud Simpson quality. You may be more likely to get a "great" Simpson meter that gets finished at one of their modification centers, as they are another set of eyes to fix problems that Simpson never did make the meters even more perfect. Triplett meters have an advantage of a perfectly linear scale, making artworks much easier. However, their extremely tight tolerances make a nice home for ferrous debris to reside and totally stop the movement. Since Triplett was bought out by Jewell Instruments, the price of their meters has gone from competitive, for American made meters, to costing arms and legs to firstborn children for models not discontinued a bit more. Just ask them about their financing options. They don't have any, but at prices ranging from $1,000 to $10,000 for a basic meter, they should. Summit meters are good and much less expensive. However, their taut band offerings have a higher rate of failure. Interestingly enough, this is not caused entirely by the band. One of the two prongs that makes the zero correction possible have a high rate of failure, making an otherwise perfectly functional meter useless. Crompton meters used to be head of the pack. Since their outsourcing to India and the subsequent adoption of the Indian mechanisms, they have been experiencing growing pains. They have corrected problems such as shallow jewel depths, which allowed a sharp shock to bounce the coil assembly right out of the jewels. This can be done by jarring the meter, such as a package handler dropping a shelf full of boxes onto the floor from a height of six feet lightly placing them on a pillow. In addition to this, anything not stocked in the US typically has an eight week lead time. Yokogawa (formerly GE) meters seem to be the best all-around meter for quality, lead time, and price. They offer a mature product that they have stuck with, making only minor changes over the years. The only problem is their catalogs. Some of their drawings are best described as abstract art commenting on the current state of the pixel difficult to read. The various direct-from-China offerings are a mixed bag, often resulting in a less than a well-rounded product. That said, they do make some decent approximations. Sifam has a good product, when you can get it. They are recovering from the business equivalent of a single mother marrying an abusive man who sells the house and moves the kids to Zanzibar, only to mail a certificate of divorce. They also get their meters out of India, but kept their movement design intact, unlike Crompton. Lead times vary from how many times a week you call them to never four months to a year unless you can find a stocking distributor or modification center on your continent. When shopping as a hobbyist, events like the W6TRW swap-meet offer a good source for meters that range from great to totally busted. The great ones are exactly that. Names like Weston, Simpson, GE, Yokogawa, api/LFE, Phaostron, Hickok, Beedee Triplett, and Sunshine can yield good meters. Look out for loose glass or anything that might let ferrous material get into the meter gap. These movements can be smaller and more delicate than a Swiss watch, and the needle should always wiggle when the meter is moved. Unless you have super-meter-samurai-skills experience working with meters, I would recommend leaving delicate work like balancing and cleaning/repairing movements to professionals. Well, I can say for sure that Jason may look forward to a long relationship with yours truly. One of the things I've been really worrying about is installing the new faceplates for my Vetinari Clock project. I've already opened each of these meters once to remove any unwanted series and shunt resistors, and I was dreading opening them again to replace the faceplates (every time you open one of these sealed units, you run the risk of messing something up). As an aside, I few minutes ago I mentioned to Jason that I'd used superglue to reattach the glass faceplate to one of my meters. In response, I heard the sound of air being sucked through Jason's teeth. I now learn that the outgassing of superglue as it cures can form a film on the inside face of the meter (using the wrong silicon compound can cause the meter's internals to completely decompose). This is one more meter that will be winging its way to Jason in the very near future. But, once again, we digress... Now I have a cunning plan -- a plan so cunning we could pin a tail on it and call it a weasel (as the Blackadder would say). As soon as I receive my new faceplates, I'm going to ship them and the meters off to Jason and make it his problem (LOL). Jason will clean and fine-tune the meters, swap out the faceplates, and make sure everything is totally tickerty-boo before returning the little scamps to your truly. If this isn't cause for a happy dance, I certainly don't know what is! But wait, there's more... I'm a "people person" and I always like to get to know the folks I'm working with. While talking to Jason on the phone, I can usually hear people chatting in the background, and everyone always seems to be having a jolly good time, so I asked Jason if he could send me some pictures and descriptions of the main suspects. Jason responded as follows: Ike Ike is the patriarch of the family, my grandfather, and one of our salesman. He was the vice president and general manager of this company back when it was known as Western Electronics and was a division of the RV Weatherford Company. When the parent company went under in 1987, he bought out his division and named it Instrument Meter Specialties. He loves talking to older Simpson 260 repair customers. Ike is our resident comedian. When the customer talks about how long they have had their meter, and how old they are, he usually tells them that they aren't very old. At 80 years old, he has most of them beat. Ike started his experience in his dad's radio and TV repair shop, which was open from 1939-1975. Dwight My dad, Dwight, started working with us after his retirement from a city public works job. He builds and re-builds speakers in his spare time and gives them to family members and friends. He will often wind his own induction coils for his speakers. He oversees the finer details of the goings on in the lab and repairs, modifies, assembles, and calibrates about half of our meters. We often find him making custom pieces for our more advanced meter repair and retrofit jobs. One of his nicknames here is Mr. Modify. Janine My mom, Janine, is Ike's daughter. She came to work with us over two years ago, leaving another job as an Assistant Administrator. She has taken over the accounting side of things as well bringing another element of comedy. During our last fire inspection, the fireman asked my mother what kind of business we are in. She promptly answered, "Monkey," with a straight face. I try not to look at the chart of accounts as it intimidates me -- my eyes glaze over when she talks about credits and debits, but the books always balance and I'm really glad to have her accounting expertise. (I was especially grateful for this expertise when we moved from our old accounting software, Dac Difficult Easy 12, to a new ERP software, xTuple Postbooks, as she was the other half of our migration team.) John John is the only non-family member of our company, but we don't let that stop us from tormenting him like he is family. He is our resident Simpson 260 Guru. Seriously, customers have called him everything from Obi-wan to master Yoda. By his last count, he owns 47 pieces of different Simpson test equipment that he's restored. John is our other full time meter technician, and he repairs, modifies, assembles, and calibrates many of our meters. Several customers have specifically thanked the "meter gods" for the restoration job they received (unfortunately, I can't convince John that they aren't just using a figure of speech). Sarah My wife, Sarah, was my high-school sweetheart and is my "other half." She prints our meter dials and maintains our re-vamped website at Multimeter.com . Sarah also manages our work calendar. She is an avid reader and has great attention to detail. Now she also spends much of her time taking care of our 22-week-old daughter -- our first child. Jason Finally we have me, Jason. I've been working here at IMS since I started high school in 1998. I still remember not having a clue what was going on and being terrified of the phone. Since then, I have learned everything I can about meters. I worked my way up from junior lab technician to head lab technician to sales associate and product designer. I am in charge of designing our circuit boards and custom products for customers. In my spare time at work, I add features to a php script that I have been creating for the past three years. This script draws our dial artworks in SVG format and has cut our artwork overhead by up to 75%, thereby allowing us to pass these savings on to our customers. When I was assigned to be half of our migration team during our move to xTuple Postbooks from Dac Difficult Easy 12, I was responsible for all of the data exporting, cleaning, and importing. I also ran the phone and Ethernet cables in our unit, which included swapping the end on a 52-pair cable. So, there you have it. Even though Instrument Meter Specialties is a small, family-owned company, they have a worldwide reputation. In addition to North and South America, they service customers around the globe, from Europe to Asia, and from Russia to Australia. Hmmm, I'm starting to envision a "Vetinari Clock on Steroids" featuring large antique analogue meters from around the world...

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