Extech EX410A DVM Don't Buy

I have good experience with the Uni-T products.

This one has close to same specs as a Keysigth one:

Looks nice, currently unavailable.

Flukes are good, except for the insane pricing. And the insane difficulty of replacing batteries or fuses.

What don't you like about the auto power off feature in the EX410A?

EX410:

I have two Extech EX470 DMM's:

I've had both DMM's for over 10 years and use them often. I've had no difficulties except with various 9V batteries. I got tired of replacing them. Over the last 5 or so years, I've experimented with two types of rechargeable Li-Ion 9V batteries.

The ones without an internal battery charger had self-discharge problems:

The batteries I'm using now, which have a built in charger, are better:

If your complaint about the auto power off feature involves some leakage current when the auto power off feature has turned off, these batteries might help.

I just measured the battery drains in my Extech EX470. Time to power off: 30 mins Operating battery current: 5.4 ma Power off after timeout: 0.02 ma Power off using rotary switch: <0.01 ma

I also have a Uni-T UT210E.

Also, some hacking is possible:

Eventually, there will be batteries and cells available in every combination of size and chemistry. Whether all combinations are usable, practical or economical, is a different problem. I didn't know Li-Ion AAA cells existed until after I searched for them. One day, they magically appeared on eBay and Amazon.

Incidentally, you might find these web pages of interest: "Low current discharge of batteries"

I think LiFePO4 (lithium iron phosphate) is a better solution for test equipment and TV remote controls. With a nominal 3.2V voltage, a single AA or AAA cell should substitute well for the usual two AA or AAA cells in series arrangement:

My main goal is to eliminate non-rechargeable batteries from my life, especially alkaline cells, which tend to leak and corrode terminals, wires and PCB's:

I have a box full of Weller WTCP series (TC202 base) very used soldering stations along with a collection of half burned out tips.

It shuts off in the middle of a measurement, and you have to rotate the very klunky range knob all the way back to OFF and then all the way back to where it was.

It's OK for one-time measurements I guess, but terrible for bench experiments.

Extech was planning to introduce some thermal imagers, so FLIR bought them to stop it. That's all FLIR really cares about.

I still have my first soldering iron, a Weller WECP-20 (so it's 40 years old). Use it as much as the Thermaltronics professional station. Comes in handy when I need something with more heat capacity.

Also have a Weller WMRP. Heats up in 3 seconds:

The Metcals are fabulous.

Nice. A fine tip would be nice but I do fine soldering with a hot air gun or a copper wire wrapped around the soldering tip (with plenty of flux).

We live in different worlds. I do mostly repairs these days. I have two ancient Weller WTCP soldering stations, three vacuum pump desoldering stations, and I have no idea how many non-motorized "solder pump" vacuum desoldering contraptions. Soldering is easier than desoldering.

I have the TS100 iron, older version of ther TS101. Uses it when I am at clients that have few tools. Even some of the big firms I work for have very limited tool selection

I agree. That's a serious problem.

Some of the Extech meters have a way to disable auto power off. It's usually disarmed by holding down one of the buttons while turning on the meter. I couldn't find anything like that for the EX410A. I'll look again when I'm more awake.

However, my Uni-T UT-210E does have a way to disable auto power off. From the user docs at:

- Automatic power-off: when measuring, if the rotary button has not pulled out in 15 minutes, the instrument will automatically power off to save energy. In automatic power-off mode, turn rotary button to OFF and restart the machine, or click any key to wake the instrument.

- Turn off automatic power-off function: press and hold SELECT key, then power-on start, you will heard 5 buzzing which means automatic power-off function is cancelled. Turn off and restart the machine, automatic power-off function will be recovered.

- The buzzer will send out 5 warnings 1 minute before automatic power off. A long buzz will be heard before power off When automatic power off function is canceled, you will hear 5 continuous warnings in every

I just tested it and found that it works as described. Maybe a meter made by Uni-T might be less stupid. The manual doesn't mention that every time you turn the meter off, auto power off is re-enabled. You need to remember to hold down the SELECT button every time you turn it on. For bench use, I don't see this as much of a problem. For my use, which involves turning it on/off many times, it's still a problem.

I mentioned that the UT-210E is hackable. See:

I didn't know that. FLIR bought Extech in Oct, 2007. After 17 years and once FLIR owns the IP (intellectual property), I would have expected FLIR to sell off Extech in parts and pieces:

For IR measurements for handheld, I use Seek Thermal:

On Sat, 05 Oct 2024 14:37:55 GMT, Jan Panteltje snipped-for-privacy@comet.invalid wrote: (chomp)

I remember and like the reassuring clicking sound of the "magnastat" contacts. If I don't hear the clicking, I know something is seriously wrong (such as the contacts welded together).

NiMH generally work well in devices that will tolerate low voltages. Eneloop cells start out at about 1.5V and expected to work down to

There are also consistence problems and matching issues with NiMH:

Fun with shorting alakline batteries:

I have a gasoline generator for running my two refrigerators. I tried using batteries and an inverter, but they couldn't tolerate the required peak surge current of the refrigerators. Generators are also useful for drying my gloves.

Ok, that works. My problem with do-it-thyself battery power systems is they usually are missing the BMS (battery management system). A BMS is mandatory for Lithium-Anything system.

I solved that problem a few years ago by convincing a neighbor to buy a "no moving parts" weather station for about $300.

I have a bad habit called "YouTube". Google allows free streaming on YouTube, but adds an overdose of commercials. The commercials are tolerable because Google allows me to skip forward with the touch of a button on the remote control. Unfortunately, my remote is by Roku, which is not very well constructed, and with the upcoming election, the number of commercial interruptions have grown substantially. I haven't counted, but I would guess(tm) that I need to push the same remote button 100 times per day. The average life of my remote control buttons is about 3 months. A remote doesn't last long enough for me to worry about charging. I stuff in whatever AAA alkaline cells I can find and use the remote until it dies.

I have 2 drones. I haven't flown either drone for about 6 years. Flying a drone in the trees is a really bad idea. Also, the county government and FCC have various restrictions that make legal drone flying without a commercial license almost impossible. For entertainment I've become rather adept at indoor drone flying. I can't find any photos. Remind me to take some photos if you're interested.

I'll pretend to be polite and not say anything about the wiring.

I'm still a kid.

This guy from Denmark has done a lot of testing, also on USB adapters:

I think they used a Curie effect magetic path to switch the heater contacts. Metcal uses Curie effect without the contacts.

Seems to me that a thermocouple and a heater would work as well.

These are the ones that give a warning beep, but there's nothing you can do to prevent it from turning itself off, after the warning?

Hillarious.

I've got it permanently attached to a thermocouple. Turn it on to measure once, then screw it. Next time . . .

Wouldn't use it for anything running on a bench test.

Could you imagine four of these things beeping at you in the middle of a crucial measurement cycle?

RL

Yes. I find the best web sites when I'm looking for something else.

Will your DCF radio clock operate at 1.2VDC (or less) at the radios "normal" current drain? Actually, yours probably uses two cell in series, so that should be 2.4VDC. The better NiMH cells provide 1.2V with a very light load:

The photos are not of a common Duracell leaking electrolyte, but rather of a premium Duracell exploding inside its metal case. There's a small chance that this 9V battery was a counterfeit, but it's too late to check.

Ummm... A tiny desktop vertical rotating turbine is not likely to produce 10 Kw of power. The unspecified size solar panel might produce 10 Kw, but a small desktop device will only deliver a few watts at best.

I've had some experience with vertical turbine generators. In a strong wind, they can't be feathered and will usually rip the base out of the roof or whatever it's mounted on. They also make far too much noise. When ground mounted, the part of the vertical turbine blades near the ground don't contribute much power.

I suggest you do some reading before you waste your money:

I didn't pay anywhere near full price for the two batteries. I don't want to explain how I obtained the batteries but I will assure you that I didn't steal them.

Again, you can't easily feather a vertical wind turbine. There's no easy way to point the vertical turbine blades perpendicular to the wind. The only way to slow down the rotation is with some form of brake, which essentially converts the wind energy into heat. Imagine your turbine dissipating 10 Kw of heat continuously.

That's roughly the way the Tempest weather station works. I suggest you look at the available data sheet, feature list, and software before you reinvent the device. Communications is via Wi-Fi: <https://shop.tempest.earth/products/hub>

See "Technical Questions" near middle of FAQ: <https://tempest.earth/frequently-asked-questions/>How does the ultrasonic anemometer work? The ultra-sonic anemometer is composed of 4 transducers housed in the top of the device. The Tempest measures wind speed and direction based on the time of flight of ultrasonic pulses between pairs of transducers. This allows for a high degree of accuracy especially in variable wind conditions. An ultrasonic sensor is very good at detecting light winds and has an advantage over mechanical sensors which require momentum to rotate their bearings. Tempest’s ultrasonic anemometer has an upper detection limit of 100mph (~160 kmph). Any wind speeds above this threshold may be outside of accuracy specifications.

Sorry, but exploding drones have been replaced by exploding pagers.

The wiring is (barely) tolerable. However, whatever animal droppings you used for flux is beyond disgusting. I suggest baptizing your wiring maze in some alcohol, which should remove the brown goo and make your masterpiece presentable.

I'm 76 and holding.

I've given up running and cycling and downsized to walking and hiking.

I still use 63/37 tin-lead solder, but have forced myself to tolerate using ROHS dross. I have separate soldering and desoldering stations on my bench, one for each blend. There's are two small fans blowing the fumes towards the wall behind my bench, which has slowly changed from white to brown. I make my own rosin flux from pine tree sap and isopropyl alcohol. It's very organic, substitutes nicely for incense and might even be healthy.

I didn't know that. I use cellulose sponges and water for tip cleaning. I also use some brass "wool" tip cleaners. For the big irons, I use a sal ammoniac (ammonium chloride) block. When I bought the box of Weller soldering station parts many years ago, it came with about 50 dirty Weller tips. I soon determined that the company that provided me with these irons had a policy of not cleaning tips. When a tip became dirty with burned flux, it was replaced with a new tip. After some experimenting, I managed to clean almost all the tips, some of which I still use today.

Yes, that's how they work.

I don't know much about Metcal except that some model soldering irons use RF heating.

It would in the 21st century. The Weller "magnastat" patent was first patented in 1960:

I believe that the largest advance in soldering technology was the hollow tip, which allowed locating the temperature sensor very close to the tip. We would not have tiny soldering tips, fast warm up time and accurate temperature control, without the hollow tip.

Jeff Liebermann snipped-for-privacy@cruzio.com Wrote in message:r

My BK. Lcr meter came with a lsd 9volt rechargable battery. Like the enloop's it should hold a charge for a long time.

Time will tell if it any better than a nimh standard cell.

Cheers