Agilent U1253B Handheld Multimeter Energy Consumption Overview

[Phyllomedusa]

I thought it may be interesting to collect and compare the battery consumption of various Handheld Multimeters. For rare occasions I always keep some spare batteries for my meters in my bag and honestly....I had been pretty happy about that habit sometimes. Last time I had been happy to have spare batteries was when I was working in the Amazon and our solar power supply was down due to a malfunctioning charge controller.... no chance to recharge my batteries.
Option a) wait for the next helicopter to bring you a 9V battery with the shipment....yes, it is as ridiculous as it sounds
Option b) ask around if there is somewhere a 9V cell as spare.....you better have luck!!
Option c) always carry some spare parts like fuses and extra batteries!!!
So all in all......battery consumption CAN be a concern but hasn't to be. So I think an overview for some meters we use could be interesting and handy


I just tested my Agilent U1253B which is often said to have a very bad battery runtime (well, works for a day and it's rechargeable).
This was to see its actual battery usage and find out how much the display brightness on the OLED really matters in terms of runtime.
So I measured:



Agilent U1253B

V~      Low  Brightness:     22,96mA       in 500V
V~      Med  Brightness:     28,45mA
V~      High Brightness:     32,72mA

V-       Low Brightness:     20,94mA         in 50V
V-       Med Brightness:     27,65mA
V-       High Brightness:    32,87mA

mV-    Low Brightness:      19,25mA         in 1000mV
mV-    Med Brightness:      21,67mA
mV-    High Brightness:     27,22mA

mV~   Low Brightness:     22,22               in 1000mV
mV~   Med Brightness:     26,18
mV~   High Brightness:    29,26

Ω        Low Brightness:     21,67mA          in 500Ω
Ω        Med Brightness:     26,72mA
Ω        High Brightness:    30,92mA

Diode  Low Brightness:     23,11mA          not applicable
Diode  Med Brightness:     31,99mA
Diode  High Brightness:    35,28mA

Cap     Low Brightness:     19,07mA           in 100µF
Cap     Med Brightness:     23,88mA
Cap     High Brightness:    27,71mA

µA      Low Brightness:     19,62mA           in 500µA
µA      Med Brightness:     25,22mA   
µA      High Brightness:    29,82mA

mA     Low Brightness:     20,95mA           in 50mA
mA     Med Brightness:     27,92mA
mA     High Brightness:    33,22mA

OUT    Low Brightness:    35,66mA            at 200Hz and 50% Duty Cycle
OUT    Med Brightness:    45,13mA
OUT    High Brightness:   48,74mA

OUT->The U1253B has a simple built-in PWM generator

Meter Off: 5,11µA
Battery: 9V (rechargeable 300mAh)

so you say it works between 20 and 50 mA, whereas the display brightness varies the consumption about ±5mA. So all in all it's not that hungry, but the 9V battery lowers the runtime considerably compared to some 800mAh AAA eneloops for example.
....just four AA eneloops with 2100mAh would be lovely to use . Regarding the trend that more and more DMM's use AAA batteries we already have a significant rise in runtime compare to 9V cells.

Is there any interest or need on more data about the U1253B?

[Kiriakos GR]

Excellent data collection.   

The DC volts is considered as the less power hungry function.
If you can measure that too, the picture will be more complete.

And lastly one question, what the word OUT stands for ?
I think that the U1253B haves the ability to output an test signal, but I do not remember the frequency or the PPV.
 

[Phyllomedusa]

...of course...I added the rest of the Functions and the used Range (as I mostly disabled Autorange and set my default ranges).

The U1253B has a simple PWM Generator. Not that fancy and powerful but sometimes pretty handy for testing actuators or servos and so on.

[Kiriakos GR]

Impressive 

The PWM Generator looks to need buckets of mA  LOL   

[Phyllomedusa]

Yepp....That's what I expected

I will compare it to the U1272A next week (whenI am back home and have my PSU to drive the U1272A). Let's see

[Phyllomedusa]

Oooo KKK,
I just tested the U1272A on my PSU and measured its current drain at 6,0V:


V~      No Backlight:         7,53mA          in 300V
V~      Backlight:            66,67mA

V-        No Backlight:         2,55mA          in 30V
V-        Backlight:            62,38mA

mV-    no Backlight:           2,62mA          in 300mV
mV-    Backlight:              62,42mA

mV~   no Backlight:           9,08mA          in 300mV
mV~   Backlight:              68,08mA

Ω        no Backlight:           4,55mA          in 300Ω
Ω        Backlight:              64,14mA

Diode  no Backlight:           2,61mA          not applicable
Diode  Backlight:              62,48mA

Cap     no Backlight:           4,58mA          in 100µF
Cap     Backlight:              64,15mA

µA      no Backlight:            2,56mA           in 300µA
µA      Backlight:               62,39mA 

mA     No Backlight:             2,50mA          in 50mA
mA     Backlight:                62,43mA

LowZ  No Backlight:             7,55mA          not applicable, fixed
LowZ  Backlight:                 66,71mA


OFF: Not measurable (Off means off it seems. From time to time the last digit on my U1253B changed to 1, but that's more an random error I guess)

Regarding the Voltage. You can run the meter down to 4V before the display starts to fade. If you enable the backlight then at 4V, the display fading increases significantly.


So all in all it runs pretty smooth. The Backlight drains a lot on the battery (roughly 60mA), so for all those dark engine room crawlers. The OLED really is a big advantage in terms of energy consumption compared to the LED backlight.
At work under daylight conditions, the U1272A with its LCD clearly is leading the field.
So again I think that AAA's instead of the 9V Block as voltage source for the U1253B would have been a much better choice.

So I think it may be time for some in-situ pictures of the U1253B and U1272A to compare the display advantages/disadvantages.... I may give a reference with my Sekonic L-758 Lightmeter to show the ambient lighting in LUX then.

...to be continued

[Kiriakos GR]

Lots of justified enthusiasm. 

Yes the damn U1272A is a very fast & well designed meter, and only if you made it to get one, you will find out why Kiriakos admires it that much.

About the low battery and the fading at below 4 volts, it sounds normal.
But there is a good point at the U1272A, and this is that is not trapped by the battery monitor so to shutdown at low battery.
And so the meter is usable, if you do not activate the back light.
What I am saying is that you have more time at your disposal, about to replace the alkaline or recharge your NiMH batteries, in comparison with the U1273A.

You PSU ammeter needs calibration   
In my review I had use the Fluke 28II for this task, so the results of my measurements to be easily verified and by others.  ( I am teasing you) 

The environmental temperature or even the brand of your batteries it can effect drastically the total battery life.
 

[Phyllomedusa]

Yes, the U1272A is a real nice meter and has his advantages.

For the measurements: I used my U1253B for that. The PSU was only used as voltage supply, as I don't trust a power-supply to be a good meter
What I had seen that the measured current was altering quite a bit (around +-30uA) so I used the AVG function.
The battery consumption of the meter in off station will be checked again as you have measured sth. there.

Regarding the batteries: Yes it works pretty nice in that way. 4V (1V per cell) is more or less designed to use with rechargebles . Around my idea with the Lipo pack as source for long term logging that tells me I would need an 2s cell. Maybe it would be interesting to slowly lower the voltage and let the U1272A measure its own supply voltage to see when logging stops. If the display is faded but the meter is still logging properly it would be enough and I could use a 1s Lipo
For the U1253B a 2s Lipo would be great. The meter switches itself off below 6,2V. So a Lipo-cell (if the meter would really run down that low) will stay with 3,1V and could be safely recharged.

[Kiriakos GR]

Even if I am on your side about battery life improvements, I have to publicly inform that Lipo-cell is not considered as safe battery option about multimeters.

Interesting enough, in scope meters some manufacturers they do use Lipo-cell .
But those instruments have a limited 300V CAT III specification.
 

[Phyllomedusa]

Yepp, I know about the "abilities" of Lipo's when they get overcharged or cracked, but as I just go up to 24V my logging applications and don't expect high creeping voltages to the batteries, it should be fine.
With a Lipo it would be small, pretty lightweight compared to a Lead Acid battery and full of power.

I think the CEM "Fluke289" counterpart (is it DT-9989?) uses a Lipo battery At least that's what I remember.....