Test and Measurement Forum

Adding correction factors

Adding correction factors

Postby jamesw » Tue Apr 12, 2011 3:49 pm

Hi, we have a number of EL026/EL030 Humidity / Temperature Converters/sensors in our lab. I'm asking how, if possible, to apply correction factors to the data as previous calibrations have highlighted offsets for each of the sensors rh values. I've only recently taken over looking after the lab conditions so I'm still not completely up to speed with the system.
jamesw
 

Re: Adding correction factors

Postby ziko » Wed Apr 13, 2011 7:57 am

Hi unfortunately this cannot be done with EL026/30, if the unit is not within its quoted accuracy then the unit would need to come back for calibration. If the units accuracy is not high enough then the alternative is to source a third party humidity sensor from a company like Rotronic or Vaisala, these can then be fed into the input of the EL037 general purpose converter which can take 4-20mA, +/-2.5V or +/-10V on each of the 4 inputs. A scaling file can then be produced to show the readings into the desired scale and units.

http://www.picotech.com/e_converters.html#el037

Hope this helps.
Ziko

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Re: Adding correction factors

Postby jamesw » Tue Apr 19, 2011 9:51 am

cheers for your help ziko, we'll just have to keep manual applying the correction factors.

I have another question though. we have the logger connect to a Risco speech dialler (EL019 autodialler) through the EL042. Although we have 3 message recorded we only get the dialler sending the first message when an alarm triggers, even if options B or C are selected for the EL042 outputs in the sensors alarm options. Currently the autodialler is sent with trigger mode nE (negative internal pull-up resistors switch in) and the multi-trigger inhibit is off. Should the the trigger mode be Po (positive nternal pull-up resistors switch in) or CP (negative internal pull-up resistors switch out) and the multi-trigger inhibit on.
jamesw
 

Re: Adding correction factors

Postby ziko » Thu Apr 21, 2011 2:59 pm

The EL042 has two modes, 1 as an EL042 independant mode and 2) as the old EL018. The EL018 was what we used to sell with the Autodialler this has become obsolete. In order to work in this mode you need to reconfigure the EL042.

You can do this by going into utilities and select Change Address:

Then Untick the box that says EL042 independant mode and then select Programme and Continue.

Hope this helps.
Ziko

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Re: Adding correction factors

Postby jamesw » Thu May 26, 2011 2:07 pm

Hi ziko

We've finally had a chance to try your suggestions and encountered some problems.
when we went to untick the box for the EL042 independent mode we found it was already unticked. With it unticked we simulated an error by deliberately setting 1 of the alarms lower than the current reading. This caused the normal alarm response we get. A buzzer from the EL042 (clicking the red icon on the enviromon screen end this) then we get the dialler calling the first number in the list. However the message given is always the first option regardless of which is selected when the alarm is set up in setting>configuration>change>advanced>locations>[sensor name]>edit>alarms>available EL042 options>message B. We as always getting the buzzer and alarm message A whenever an alarm triggers regardless of what the alarm settings are.
As a quick test we tried with the EL042 independent mode box ticked and had no buzz or dialling when the alarm triggers.

can you help with this?
jamesw
 

Auto dialler message

Postby jamesw » Thu Jun 30, 2011 3:03 pm

Any update on this?
jamesw
 

Re: Adding correction factors

Postby ziko » Mon Jul 04, 2011 2:22 pm

Hi yes sorry this one must have slipped the net!

I investigated this in a bit of detail using one of our scopes and monitoring all three outputs.

It seems like the alarm condition works if you acknowledge the alarm, if however you do not acknowledge the alarm and reprogrammer logger the alarm condition will be latched.

I have reported this as a bug so this should be fixed on a subsequent release of the software.

Kind regards
Ziko

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