Poll: Handheld meters with minimally-annoying auto power off (APO)

[Fungus]

Following up on the handheld-vs-benchtop meter debate...

Let's make a list of handheld meters that will auto-power-off silently then wake up in the same mode with a single button press, ie. they aren't annoying to use on the bench all day long.

Meters that DO this:
Brymen: BM857  BM789  BM235  BM869s


Caveat: They lose some settings, eg. manual/autorange mode and min/max/rel values (but if you're doing a long min/max session you need to temporarily disable APO anyway).

Meters that power back on with a button but lose the secondary function setting (eg. they APO in continuity mode then come back on in Ohms mode):
Fluke: 87, 187, 189, 289


Meters that don't have APO (or can disable APO permanently) and have a really long battery life (1000 hours or more):
Fluke: 27FM   37FM

Other: DT830 ("Harbor Freight")


Meters that beep when turning off and/or require you to turn the dial to wake them up:
Fluke: 101
Kaiweets: HT118E


Special hell:  Meters that beep twice - once to warn you they're about to APO then again a minute later when they actually do it.
Aneng: AN860  AN870  V04A   AN8008
Surpeer: AV4

[Fungus]

I'll be testing my meters today, feel free to post results for other models.

Edit: Yes, there's meters that allow you to temporarily disable APO by holding down a button at power on. I haven't included those because that's annoying too. I don't think it excuses them from not doing it properly.

[sonpul]

BM789 does this. off silently.
Every day, I do not turn off the DMM several times and many times a day I turn it on simply by pressing the yellow button.

[nctnico]

Following up on the handheld-vs-benchtop meter debate...

Let's make a list of handheld meters that will auto-power-off silently then wake up exactly where they were with a single button press, ie. they aren't annoying to use on the bench all day long.

Any meter that turns of automatically is annoying for bench use. The same for meters that run out of batteries.  I learned that a long time ago.

[Fungus]

Any meter that turns of automatically is annoying for bench use. The same for meters that run out of batteries.  I learned that a long time ago.

The point is that some are much more annoying than others.

[RoGeorge]

Metrix mtx3283 DMM has a setting to disable the auto-off.

[bdunham7]

I don't know if your analysis is really correct here--none of the meters will actually go back to exactly what they were doing in all cases AFAIK.  On the Fluke 187/189, for example, it will go back to the first function of the dial setting that it is at, but if you have selected another function or manual range, it will forget that.  Try it--set the meter to the VDC dial setting and then use the blue button to select AC+DC, then let it power off.  When it comes back on, it will be back to plain VDC.  Even if some other meters manage to get past that test, what happens if you had it in a manual range or were using REL or MIN-MAX?  I'm betting at the very least it will lose the old REL and MIN-MAX values and it certainly won't have updated during its off time.

I don't personally see much difference in annoyance levels since if I'm observing a reading over time or looking at MIN-MAX, just having the meter power off at all is more annoyance than I care to deal with.  The only meter I use alonside bench meters for long-term observation is the Fluke 27, since it just stays on virtually forever, doesn't tip over and won't mind too much if I spill coffee on it.

[tautech]

Dunno, use meter then turn it to Off.

However there are times when ....where is that DMM ?
Somewhere else last used and distracted walked off and left it running to be discovered days later left in some range but APO. Press the range button (Ohms, Diode, Continuity) for Ohms mode and it wakes right up again in the mode in was left in but it is a Fluke 15B.

[wraper]

I decided that it's easier to disable APO completely as my meters run on rechargeable batteries and replacing them more often is less of a bother..

[gamalot]

   Kyoritsu KEW1021R will beep twice!

[Gyro]

The UT61E does not APO because its optical data output is permanently enabled, whether its interface is inserted or not. APO can be added with modifications to both the meter and the interface (extra IR LED and phototransistor).

[RoGeorge]

none of the meters will actually go back to exactly what they were doing

That is incredibly dumb, indeed.  A 1 million writes eeprom like the ones in the TV costs peanuts.  Could write after each button pressed and never wear out.

Another one is the impossibility to disable the warning for a plugged cord in the A socket when switching to volts.  Well, I don't have two cords and keep switching them, I have 3 different cords and I would like to keep them plugged at all times.  My A cord has a different handle, no way to mix A and V cords by accident.

[bdunham7]

Another one is the impossibility to disable the warning for a plugged cord in the A socket when switching to volts.  Well, I don't have two cords and keep switching them, I have 3 different cords and I would like to keep them plugged at all times.  My A cord has a different handle, no way to mix A and V cords by accident.

I had a setup like that on a meter I mostly used for automotive.  Then one day I was checking a wall outlet in an difficult-to-reach area in an awkward position and of course with an unfused Harbor Freight meter.   

I can't imagine a manufacturer adding either of your feature requests to any of their products.  Why would they want to decrease reliability and increase liability to implement features the vast majority of users wouldn't even know were there?

[sonpul]

Try it--set the meter to the VDC dial setting and then use the blue button to select AC+DC, then let it power off.  When it comes back on, it will be back to plain VDC.

BM789 remembers both AC+DC and all other additional modes on the selector. And after the usual shutdown by the selector and after autopower and after turning on the button after sleep. Everything from the selector remembers.
From the buttons above the selector, for example, Range, AutoHold, Rec does not remember. But this is not necessary.

[sonpul]

The UT61E does not APO because its optical data output is permanently enabled, whether its interface is inserted or not. APO can be added with modifications to both the meter and the interface (extra IR LED and phototransistor).

I had UT61E. If you activate APO on UT61E, it beeps unpleasantly, does not remember the selected mode.

[Anthocyanina]

I don't know if your analysis is really correct here--none of the meters will actually go back to exactly what they were doing in all cases AFAIK.  On the Fluke 187/189, for example, it will go back to the first function of the dial setting that it is at, but if you have selected another function or manual range, it will forget that.  Try it--set the meter to the VDC dial setting and then use the blue button to select AC+DC, then let it power off.  When it comes back on, it will be back to plain VDC.  Even if some other meters manage to get past that test, what happens if you had it in a manual range or were using REL or MIN-MAX?  I'm betting at the very least it will lose the old REL and MIN-MAX values and it certainly won't have updated during its off time.

I don't personally see much difference in annoyance levels since if I'm observing a reading over time or looking at MIN-MAX, just having the meter power off at all is more annoyance than I care to deal with.  The only meter I use alonside bench meters for long-term observation is the Fluke 27, since it just stays on virtually forever, doesn't tip over and won't mind too much if I spill coffee on it.

fluke 117 also does this, can be brought back to life with a button, but will only go to the primary function of the position the knob is at

[mwb1100]

I'm surprised no one has mentioned the Brymen BM235.  Best APO behavior ever: APO kicks in after 30 minutes of inactivity.

Many meters consider "activity" (for APO purposes) to be button presses or selector rotation.  However, the BM235 will reset the inactivity timer for any of these:

1) Rotary switch or push button operations
2) Significant measuring readings of above 8.5% of ranges
3) Non-OL readings for Resistance, Continuity or Diode function
4) Non-zero readings for Hz function
5) Electric field signal present for EF function
6) Significant movement indication as in Phase Rotation functions

Meaning that it more or less won't APO if you are actually using the meter.  The readings don't even have to change - they just need to be something significant. If it does APO, there's no beep (why would you need to be notified? you weren't using it anyway), and it can be turned on by pressing the SELECT button.  Oh, it will disable APO if you're using the MIN/MAX recording.  I think most (all?)  meters turn off APO if you're doing any kind of recording.

It has a decently long backlight, too (10 minutes).  Backlights that turn off after only 15 seconds are just plain stupid.  Even turning off after 30 seconds is irritating.  Let *me* worry about the battery I'm using up with the backlight.

[Fungus]

I don't know if your analysis is really correct here--none of the meters will actually go back to exactly what they were doing in all cases AFAIK.  On the Fluke 187/189, for example, it will go back to the first function of the dial setting that it is at, but if you have selected another function or manual range, it will forget that.  Try it

Some very good points. I'll try it.

The Brymen will obviously remember the function setting - it remembers it when you turn the dial or even power it off.

I'm surprised no one has mentioned the Brymen BM235.  Best APO behavior ever

Many meters consider "activity" (for APO purposes) to be button presses or selector rotation.  However, the BM235 will reset the inactivity timer for any of these:

1) Rotary switch or push button operations
2) Significant measuring readings of above 8.5% of ranges
3) Non-OL readings for Resistance, Continuity or Diode function
...snip

Brymen calls it Intelligent Power Off ("IPO"). My BM857 does it, too.

(despite not being one of the curvy "modern" ones that people seem to be obsessed with)

[BillyO]

All 4.5 digit meters.

Brymen BM786 - shuts off (after a long time) without a beep.  Comes back where it left off pushing the select button (did not try others)

Kaiweets HT118E (I think it to be the best meter for it's price) - shuts off with beep, no warning beep (but I did step out of the room for a minute).  Comes back on to default function by pushing any button.

Surpeer AV4 (don't judge) - Shuts off beep, has warning beep about 1 minute before shut off beep.  Comes back on to default function by pushing the "PEAK" button.

[Fungus]

Some very good points. I'll try it.

Yep, you're right.

My Brymen keeps the function setting correctly but loses any 'Rel' values, etc.

The Fluke 187 powers back on when I press a button but it's in the default function for the dial position. eg. If it powered off in continuity it will power back on in Ohms. That would be annoying if I was looking at AC+DC or something like that. I'll demote it.

I'm betting at the very least it will lose the old REL and MIN-MAX values and it certainly won't have updated during its off time.

Yep, those values are lost. You'd have to temporarily disable APO if you were doing that sort of measurement. It only takes a couple of seconds to do though so I don't think it's a biggie unless the battery is about to die.

[Fungus]

Brymen BM786
Kaiweets HT118E
Surpeer AV4 (don't judge)

Added.

Doesn't the Surpeer beep on every movement of the dial, too? They really love the sound of the beeper!

[BillyO]

Doesn't the Surpeer beep on every movement of the dial, too?

Yes, it does.

But safety in industrial settings and common sense aside, it's not really that bad.

[vk6zgo]

My ancient Fluke 77 will not auto power off unless there is a zero reading on the display AND no other activity for a reasonable length of time.

The first time I ran into an early model UNI-T, I was surprised that it quite blithely shut down right in the middle of testing some equipment ----apparently, it was just a timer.
"Great fun" adjusting something, only to have the DMM shut down, just when you were getting close to the right setting.

The same meter would start giving incorrect resistance readings due to a dying battery well before its "LOBAT" display came up, and it went through batteries a lot faster than the old 77, which is probably why it used the timer.

It put me off UNI-T, but it was, as I have said, an early model.

[BillyO]

It put me off UNI-T, but it was, as I have said, an early model.

What put me off UNI-T was the TOTAL lack of any kind of support.  I think that company is run by a bot.  A not entirely intelligent one either.

[Psi]

Auto power off doesn't annoy me anywhere near as much as default to AC current. :Rage: