Autoranging

The dataTaker DT82E is a smart data logger designed especially for environmental monitoring

Autoranging

Postby nseii » Thu Mar 15, 2018 2:22 am

I have 100 DataTaker 82E's installed. Each is monitoring a voltage that is within the 30 V range associated with 2HV. On quite a few systems everything is entirely consistent but in some of them there is an occasional overrange indication which would indicate a voltage in excess of 30 V. Is there any possibility that this error is generated by an issue with the autoranging rather than the input voltage actually exceeding the maximum range? I am just checking to see if there had been documented issues that would shorten my investigation.
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Re: Autoranging

Postby Roger » Thu Mar 15, 2018 3:00 pm

Good afternoon nseii

You could try locking the gain to 30VDC range.
That would take auto ranging out of the equation

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Re: Autoranging

Postby nseii » Fri Mar 16, 2018 2:19 am

That was what I have planned but I was just seeing if it is a documented issue. I will proceed as suggested.
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Re: Autoranging

Postby Roger » Sat Mar 17, 2018 7:53 am

Good morning nseii

I've been thinking a bit more about this problem.
The autoranging is very stable and has worked well for many years.
The DT100's had autoranging and that is now over 30 years ago.

The DT80 range has three ranges. It samples and check to see if it needs to set up or down a gain range for best accuracy.
It then samples again if it needs to. It then remembers that gain setting for the next sample.

If you signal has suddenly changed between the two samples then you could get an overrange error.
This would indicate that there is noise in you signal and zi would be looking at the wiring, shielding and where the noise is coming from

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Re: Autoranging

Postby Rudy Gunawan » Mon Mar 19, 2018 12:46 pm

Hi nseii,

Other than Roger explanation, common voltage may also become the cause.
If you have shared configuration, please check if all sensors have the same common voltage.

Best regards,
Rudy Gunawan
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Re: Autoranging

Postby nseii » Thu May 24, 2018 7:08 am

my inputs are :
1*v : Charge Voltage for a charge controller (from which a charge current is derived).
1+v : Load Voltage (from which a load current is derived).
1-HV : Battery Voltage (a near constant ~14.5V signal).

and

2*Hv : Solar panel array voltage (alternates between ~0V and ~14.5V).
2Hv : Sensor Input voltage (Ion Chamber input voltage, a near constant 7V).

The over range indication happens exclusive on 2*Hv and 2HV. They were both set to auto range and now are both set to the GL30V static voltage range.

I am writing this comment, not so much for your follow up but just to clarify the situation for those that might care.

If anything should occur to you as a result of this communication, do please let me know.
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Re: Autoranging

Postby nseii » Thu May 24, 2018 7:18 am

I deleted a draft reply and didn't include 1 element that I had in the draft. The wiring is the same in the system with 2 exceptions. We have different size solar panels which are used to charge the batteries and we have different charge controllers that manage the solar panel output and provide the batteries with charging. If there is noise induced into the system the main suspect would be the charge controllers, of which we have 3 different models.
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Re: Autoranging

Postby Rudy Gunawan » Wed Jun 20, 2018 11:23 am

Hi nseii,

Other than charger model, can you please investigate for a potential of ground loop?

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