What’s the most-used tool on your bench? For me, it’s probably a multimeter, although that’s maybe a tie with my oscilloscope. Maybe after that, the soldering iron and wire strippers, or my favorite forceps. Calipers must rate in there somewhere too, but maybe a little further down. Still, the top place, and half of my desert-island top-10, go to measuring gear.
That’s because any debugging, investigation, or experimentation always starts with getting some visibility on the problem. And the less visible the physical quantity, the more necessary to tool. For circuits, that means figuring out where all the voltages lie, and you obviously can’t just guess there. A couple months ago, I was doing some epoxy and fiberglass work, and needed to draw a 1/2 atmosphere vacuum. That’s not the kind of quantity you can just eyeball. You need the right measurement tool.
A few weeks ago, I wrote about my disappointment in receiving a fan that wouldn’t push my coffee beans around in the homemade roaster. How could I have avoided this debacle? By figuring out the pressure differential needed and buying a fan that’s appropriately rated. But I lacked pressure and flow meters.
Now that I think about it, I could have scavenged the pressure meter from the fiberglassing rig, and given that a go, but with the cheap cost of sensors and amplifiers, I’ll probably just purpose-build something. I’m still not sure how I’ll measure the flow; maybe I’ll just cheese out and buy a cheap wind-speed meter.
When people think of tools, they mostly think of the “doers”: the wrenches and the hammers of this world. But today, let’s all raise a calibrated 350 ml glass to the “measurers”. Without you, we’d be wandering around in the dark.
“What’s the most-used tool on your bench? For me, it’s probably a multimeter, although that’s maybe a tie with my oscilloscope. ”
Or the clamp meter.
https://youtu.be/kawFTI5-kqU
Or your tongue.
https://en.wikipedia.org/wiki/Tongue
for roughly measuring pressures a super simple manometer made from a U-shaped piece of vinyl tubing with water in it does really well. That would be ideal for a half-atmosphere measurement. Granted, cm of water isn’t a super intuitive unit of measure but it is directly measurable.
How many cm of water is 1/2 atmosphere?
Spoiler: alot more than is convenient
You could coil up the tube to reduce the space requirements. Or you could put a cup of water in the vacuum and heat it to 355 K. If the vacuum pump doesn’t like water, add a cold trap. How deep does a vacuum cleaner go?
Or you take the vacuum out of an old vacuum flask and mix it 1:1 (by volume, not by weight) with air :o)
You cannot coil up the tube. All that matters is the height of both ends of the tube. It could be coiled, run into a big container (sealed), lay on the ground for 50 feet, it doesn’t matter.
… ever tried to blow out a coiled up garden hose?
Get the center of the coil horizontal and fill it half with water. This may be done by filling it full and slowly blowing air in one end. When the air reaches the first low point, it bubbles to the next high point, then pushes the water further to the 2nd low point and so on. The pressure needed will be the sum of all the pressure drops across the bubbling parts of the coil, diameter times number of windings. For vacuum suck water out on the other end instead, principle stays the same.
One atmosphere is about 10m of water. Measuring half an atmosphere with a column of water will be impractical in most scenarios. But it is great to measure lower pressures. Or you could use a column of mercury.
Huh. Lol. . My ceiling inside is 8′ and it’s 16′ to the peak of the garage where I actually work on crap.
Entirety of HACK-aday thwarted by lack of a two story structure or a modest ladder or a stick.
Or whatever just buy a vacuum gauge from Alibaba. Which isn’t a hack.
Oh, and awesome artwork. Slide rules are the essence of guessing and “good enough”
Punchline:
Mathematician: I’ll never get to her.
Engineer: I’ll get close enough.
>Engineer: I’ll get close enough (to her)
Said no Engineer ever.
I think these days the most used tool on everyone’s bench is their computer/phone – the reference device that aids in the use and setup of all other things. Maybe in some cases it will be the Machinist bible or similarly specific bound paper tome of knowledge. But really the reference material that helps you figure out if Craig’s water in tube pressure meter might be good enough for the job at hand before you build it or give you that simple solution you didn’t think of on your own. Both of which are even more true when dealing with more complex and expensive construction/problems – trying to reinvent the wheel might be fun sometimes, but generally the proven solution(s) are the right way.
Following that I’d say pencil and paper, white board and marker type concept – turning the thoughts into a more cohesive plan before you start. And then and only then do you move on the measurement tools that help put real world numbers into those ideas – which is also where for me the good quality multitool often becomes my first tool to reach for – can’t measure the voltage of this wire with insulation on or remove a screw without a tool etc and the good multitool is universal enough I end up using it rather than getting out the correct toolbox for the problem at hand in many cases.
Though calipers (I prefer dial to digital, though vernier would probably be fine I’ve never owned one), multi-meter and the bench power supply (with a box full of leads) along with a precision screwdriver collection are always on my usual desk along with an IR thermometer and there are magnifier lamps at most workspaces I might use – though I still have eyes good enough I don’t use them as magnifiers much.
“half of my desert-island top-10, go to measuring gear.”
Come on Elliot! Don’t leave us hanging! Tell us the list!
An old 6 Sigma adage: you can’t improve that which you can’t measure.
That’s MBA speak.
Real world comeback: ‘There is no metric that can’t be gamed.’ e.g. What % of total effort at MS is spent gaming R&R? Certainly, more than 50%, likely more than 75%, perhaps more than 90%.
The trick would be to find an employee metric that, in the process of being gamed, gets management what they want.
It’s possible but requires managers smarter than employees. Nonstarter in tech.
Your don’t have any idea what you are talking about. I worked at Motorola (arguably the major proponent of Six Sigma when it was first being widely adapted) for over 30 years, starting as an engineer. I became a manager with P&L responsibility for about $300 million in annual sales and if you knew anything about Six Sigma you’d know that without real data any “results” soon fall apart. Six Sigma is structured enough that we never had a problem spotting sloppy work, and in fact most of the engineers were more serious about it than many of the managers were.
This reads like the Navy Seals copypasta.
That has nothing to do with OPs point.
You can’t game metrics that you aren’t measuring.
“What gets measured gets managed — even when it’s pointless to measure and manage it, and even if it harms the purpose of the organisation to do so”.
If you start measuring the wrong thing, it no longer matters that it’s wrong, only that the measurement looks better to the people who don’t know what the right thing even is, but who do know how to sign a paycheck.
For phrases on measurement, my favorite will always be “Measure twice, cut once”. Applies to a remarkable number of scenarios, from woodworking to personell management. Also, deviant adult activities. Actually, especially deviant adult activities.
To measure flow, wrap some heater wire around a diode and measure the forward voltage:
https://www.edn.com/use-a-heated-diode-as-a-flow-sensor/
Airflow changes the temperature, and diodes have a tempco of -2.2mV/C.
That might work as a sensor, but only after calibrating it. While you may know the power in the wire, you don’t know the thermal conductivity coefficient. Even if you calibrate the temperature measurement against some known references, you still wouldn’t know how to convert the measurement to m/s airflow.
Also, you don’t really need the wire, you can just drive a current through the diode and measure the resulting voltage across it. Alternatively, you can use a PTC or NTC resistor, if you know the voltage and measure the current or vice-versa, you can work out the resistance, from that, the temperature, and the thermal resistance. From there, you again need calibration to work out the flow, assuming the medium is constant (gas composition, temperature and humidity).
The most important tool on my work bench that is used every single time I sit there is a good lighting system. You can’t do anything without good light.
yep, i need to use my magnifier lamp to get anything done. being farsighted my eyes dont work well at short ranges. i need to use readers or the magnifire or both and in at least one instance a 3rd magnifier for some really fine soldering. bought a usb microscope i thought id get good use out of but ive only used it a couple times for final inspection.
So true, and the amount of light required seems to increase with age. Well, that and the thickness of my glasses.
Single greatest thing I did in my shed & garage is paint the walls white, 2nd only to grabbing stacks of fluorescent fittings being pulled from an office renovation and ensuring I had all the lumens to bounce off the shiny white walls.
No-one has ever complained about being able to see too well in a workshop.
my most useful tool on my bench seems to be my flat bastard file, it never gets put away for some reason.
my most recent project was making a bracket to enable me to put a gpu (fortunately an older 1060) in a 9 liter case intended for office use. sure i could have got a half height gpu, but that would cost money, where as i had the 1060. i figure if i could rotate the flexatx psu 90 degrees and use a riser i could get everything to fit, but i had to cut out the half height slots and create a bracket out of a piece of sheet metal scrap with a hole pattern for the psu and a gpu bracket (really just a hole with a thumb screw to catch the base of the gpu side bracket and a piece of bar stock with tapped holes to engage the gpu and another set at 90 degrees with counter sunk holes so the screws mounting it to the bracket would be flush and not get in the way of the gpu). the project culminated with a kludge adapter cable to source gpu power from an unused cpu power connector (the only place left on the diminutive psu to get 12v from).
its amazing how little precision i used. i tried to use a square to keep my lines straight, but there wasnt a clean reference surface on it after i cut it out with a dremel. so i clamped the file to the desk and made one. from there i was able to draw a line and get a reference for the other axis (also using the file and the dremel to wipe out some high spots). anyway now i have a computer for my smoke room and the e-waste gremlins are kept at bay.
I would love to see a hackaday article on LVDT measurement indicators used in metrology labs, and by some very exacting machinists, like Robin Renzetti (robrenz on YT). I find them to be a perfect topic for a site like this that is nexused around electronics, but has ventured out.
LVDT measurement indicators are about the coolest electronic measuring device I know, other than the hyper exotic stuff like laser measurement systems and other crazy things. I have a feeling a lot of people here would be able to understand how they work and be able to explain how to build them and calibrate them. That would be a really cool article!
“When people think of tools, they mostly think of the “doers”: the wrenches and the hammers of this world.”
Electrical/electronic department always have multimeter, often personally issued and mostly start their job with basic tests. Less often they are critical to results but still they will cross check panel mount readings with their instrument. They prefer digital to analog (for various reasons) but are aware that analog has it’s uses.
Mechanical department on the other hand never bring pressure gauge for trouble shooting. They will relay on reading of panel mount manometer (no matter how old and dead it looks like) with their life – but prefer not to look at it unless necessary. But if there is no panel mount manometer (or there is but not even them can pretend they are reliable) they would go fully Luke Skywalker and trust their feelings rather than bring pressure gauge. They prefer mechanical manometer and have no trust in digital one (“they are not precise”). Yet they use binary to measure on regular basis – they either have pressure or don’t.
It always amazes me how much it takes to force them to test things. I am sure they accepted pyrometers only because preferred option hurts too much (you touch and if it burns means it’s above 80 [C] – now you spit and if it evaporates fast it’s above 100 [C]).
At least this is my experience – maybe I was unlucky.