Test Equipment for a High School Engineering class?

[josh.pruim]

I'm a student in High School with a very big interest in Electrical, Mechanical and Software Engineering. The engineering class that I'm in has those cheap $10 multimeters that you can buy at cheap electronics stores, and that's about the end of test equipment. The leads on those are frayed beyond belief and the tips on the probes are beyond dull. I've been bringing my personal Fluke 77 Multimeter (I do not doubt that this meter will outlive me.) to measure simple things in my projects and other projects because I don't think the crappy meters are safe. As of now, the class is getting into Arduino programming and some students are having trouble with their I2C connections not working at all, and you generally need a scope/Logic analyzer to diagnose that issue.

Seeing as I'm graduating school in less than two months, I want to work on getting my school's engineering class some decent hardware.

What are some pieces of equipment that I should look at getting (I know we need new meters, but what kind would be best? After seeing the Fluke 28-II's resistance to abuse, that may be one of the meters on the top of the list.)

I'm just trying to get ideas here, I'm not worried about pricing (We're applying for many grants to get money to buy new stuff and we could also do some hunting for educational donations/discounts.)

[Fsck]

the 28-2 is overkill for indoor use. it's designed as a super ruggedized outdoor-abuse model, but is basically an 87-5, which can also take some serious abuse.
if you have cash to throw at it, the 87-5 will probably take any moronic HS student's abuse, but a 179 can serve as a cheaper land of fluke alternative.

however, all Flukes are expensive, but do have that lifetime warranty, not sure if they have a decent educational discount but I somewhat doubt it.

the more important question is always: how much money per station?

[EEVblog]

the more important question is always: how much money per station?

That's the question.
IMO better to spend the per-station money on as many tools as allow. Quality matters, but attrition will ultimately happen regardless of the quality.
Better to have a cheap scope and cheap meter than one expensive meter for example.

[rgmolpus@flash.net]

I remember the days of helping in my Tech School's workshop; the old saying about fools being so creative to make all protective measures useless must have been composed in one...

#1: If you can buy workable but cheap multimeter for $10/15 each (freight direct from China!), do that, and be prepared to replace all of them every year. The last class at the end of the semester might be an autopsy session, where the meters that dies interesting deaths are disassembled by the students as a coda to that semester's lessons. Be willing to sacrifice a meter during the MANDATORY safety lecture so everyone will know the stench of a fried meter.

If you want to supply Flukes, keep some of the cheap meters in stock as sacrificial items, for those confused few who 'test' fuses for adherence to overload specifications....

#2: Buy Large spools of test lead cable, and plenty of banana plugs , alligator clips, and micro-grabbers, and have one of the soldering class lesson be "how to make your own test leads". After students finish that days' lesson, they'll teat the leads with greater care...

#3: Transformers are your friend! Make/Buy isolation transformers for each workstation, to prevent someone form creating Dr. Frankenstein-sized arcs when they mis-wire a circuit (they will!) Place a fuse or thermo-reset circuit breaker inline to stop Reddy Kilowatt from shaking people's hands!

#4: The most rugged power supply I ever saw was an old EICO battery eliminator that used a variac and a HUGE bank of rectifier diodes and a heavy inductor to produce 0 - 50 volts. If it was plugged into the wall outlet, not much could blow up and burn; the dozen we had survived the most amazing abuse.  Inductors can be your friend.

#5: Light bulbs will be your friends - as current limiters, indicators, temporary fuses. Buy lots of small wattage bulbs, and use them liberally in your educational/example circuits. Diodes fry, light bulbs get brighter....

#6: Don't provide hand tools! the students should buy their own! Require that all hand tools be marked with their owner's name, in a permanent fashion (provide an engraver at the beginning of the semester, perhaps), but _don't _ loan out tools! After the first Semester, the students should have their personal toolkits; as long as the quality is decent that should be their problem. You might have example kits (bare minimum and gold-plated grade) for them to inspect.


Good luck!

[AG6QR]

At some schools, any handheld meters have a habit of growing legs and walking away.  A bench meter, even if it has mediocre specs, may be more suitable, simply because it's more likely to remain on the bench and not escape in someone's pocket.  Something like an Instek GDM-8034 might be a reasonable choice for a lab.

Regarding Fluke's ruggedness and safety, they are legendary.  However, most high school electronics courses can be done at low enough energy levels so that there's no danger of even the cheapest, worst meter dangerously exploding in a student's hand.  If the experiments are done with low voltage current-limited supplies, either wall-warts, batteries, bench supplies, or similar, then a cheap meter may not present a huge danger to the students.   There is a lot of learning that can happen with even a $20.00 multimeter, but as has been suggested, it should probably be considered a disposable item that will be replaced at least once per semester.  Getting two or three per workstation would allow simultaneous measurements of voltage and current.

I'd say a basic lab bench for DC circuits needs at least a bench power supply with adjustable voltage and adjustable current limits, one or two multimeters, a breadboard, lots of test leads/stackable banana plug leads, and a number of passives, switches, LEDs, motors, transistors, etc. 

For AC circuits, a signal generator and oscilloscope should be added.  The frequency range/bandwidth isn't too critical for learning the fundamentals.  In fact, keeping most experiments in a moderate frequency range can help in learning the basics without being distracted by parasitic effects that surface at higher frequencies.

[nowlan]

My local tafe takes in high school students for some basic electronics, and soldering classes. Seems silly for a high school to spend money replicating it.

I suspect a high school class is only introducing concepts such as voltage and current. In which case a 9v battery, a multimeter, and some leds, resistors would be enough to illustrate the fundamentals.