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Product : Pm1000Serial Number : 100008202673Firmware : VER 4.26Software : 11-144Accessories : Breakout box
Item Under Test : No leads into meter Zero input results.
And leads connected and no -load
Analyser Set-Up : Simple no leads connected to meter and no-load with breakout box.Measured Values : 38.6mV, 670uA, 8uW with no leads connected to meter.
115VAC, 660uA, 16mW with your breakout box and no load applied.
When I plug in my usb charger I get 76mW and I know from our testing house(which uses recently calibrated a Chroma systems power analyzer) reads 60mW not 76mw.
Question : NEED to have zero reading for current while there is zero current being consumed(NO-LOAD)
I am trying to make measurements for California Energy Commission testing of our USB powered rechargeable flashlights.
I need to resolve to the mW.
But as you can see with no inputs connected to the meter I always read 670uA.
Not zero.
So when I go to measure the no-load power of our charger which should read 60mW, I read 76
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Dear Larry,
Non-zero readings are quite normal on a PM1000+, and in fact getting a zero reading on any instrument is impossible without artificially making it zero in the instruments firmware when the value drops below a set value. This is controlled by the 'blanking' setting on a PM1000+, and because you seeing these readings, you must have blanking disabled.
The no load current reading should be much less than the 16mW you seeing. With a 260V input I am measuring about 280uW of offset with 37uA of current. This is using the external shunt input from a Voltech breakout box with no load connected. To achieve these readings I had to set the current scaling factor to 0.0125 (because the default readings assume a 12.5mOhm external shunt and the breakout box has a 1Ohm shunt). Could you test out this configuration and confirm you have the same readings please? If you are seeing 16mA then you either have a faulty instrument or the breakout box is wired in such a way that a load current is begin drawn.
Best regards,
Tim.
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Tim,
I have set the current scaling to 0.0125.
With voltage applied and no-load at breakout box. I get 117 Vac, 4.2mA.
With no voltage applied to breakout box i get 8 mVAC, 4.58 mA and 13 uW.
And with no connections at all at meter input, I get 0 Vac, 4.6mA.
Help cannot use meter with an offset.
We just sent in Florida for Calibration. Unit was like this before cal and same after cal.
Please help!!!!
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Hi Larry,
When you have nothing connected to the instrument, try shorting VHI to VLO, and EXT-hi to EXT-lo. Check that the readings are much smaller then. This verifies the instrument independently of the break out box. If your readings go down to the levels I have suggested then you know the instrument is OK.
There is a trap you can fall into with this though. The unconnected readings are likely to be DC offset values and not at the same frequency as the measured signals. This means that any power offset you see should not be added directly to the power reading of the flashlight, but adds according to the square root of the sum of the squares. i.e. Reading squared = Offset squared + Power squared. This means that the offset readings you see will not effect the readings by any where near as much as they first appear.
Let me know how you get on and we can continue from there. What is the serial number of your breakout box?
Best regards,
Tim.
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Tim,
With shorting VHI to VLO, and EXT-hi to EXT-lo.
Readings are: 10.5mV, 650ua and -2.7uW.
Breakout box S/N is 100008800890.
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Hi Larry,
Those measurements suggest that the PM1000+ is working normally and should meet the low power standby measurement requirements. Try connecting the voltage but leaving the external shunt inputs shorted. This will make sure the voltage input isn't causing the current reading to go up for some reason. You should then measure 117V and a few tens of uA. If this is OK, go back to connecting the breakout box normally but no load again to check the problem is still present. Also check you have auto zero enabled in the instrument configuration (Menu, System Configuration, Auto Zero).
If you would like to give me a call when you are with the instrument to help diagnose the issue then you can call me on +44 1235 861173 and select the option for technical support.
Best regards,
Tim.
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Tim,
Pleasure talking with you.
I read about 2mW high, well within my needs.
I am ready to go..
Thank you for the help.
Have a great day.
Larry
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Tim,
Was wondering....
How do I setup a test for 24 hour integration?
Can I use Clock Start Method from the remote software.
The PM1000IEC61000 software included disc will not run... NiVisa problem.. Tried on two computers??
In other words How do I get the test to stop at 24 hours?
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Hi Larry,
You could try installing the latest NI VISA versions from the NI website to get the software working. I guess it's Windows 64 bit you are trying to install it on? What are you trying to measure - is it still the low power standby? If so, this is the wrong software package as IEC61000 is harmonics and flicker. You will need the PM1000+ standby power software for IEC62301, or just use the products integrator function that you are looking at. You can setup the integrator using the clock start method and then configure the clock start duration to be 24 hours. You could also manually start and stop the integrator with Hrs enabled as a measurement. You then wait for at least 24 hours to expire and divide the Whrs figure by the Hrs measurement to determine the average power.
Best regards,
Tim.
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