WERC's historic PIR measurements

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 EKY Notes:

In July 2017 We reinstalled the radiometers at UKmet and Imn Met. I had them sent back to Eppley for recalibration/repair. I had Rob make up some new cables for the radiometers in 2016. They were wired incorrectly, and nothing seemed to be working right. He had them wired to correct for "Dome Temperature" (optional) instead of "Case Temperature" (required). He originally made them for case temperature, but had Allen rewire them for the dome temperature adjustment. Nothing was working properly. Allen and I made new cables in 2017 and wired them properly, things worked. 

 Email Correspondence about this

The cables that we took up were correct and I had Allen change them. My fault. rob

On Thu, May 25, 2017 at 7:23 PM, Emily Youcha <ekyoucha@alaska.edu> wrote:

Who said to do that?

On Thu, May 25, 2017 at 7:05 PM, Robert Gieck <regieck@alaska.edu> wrote:

That's why the cable I made last year and we changed were wrong.... we moved them to the dome.. rob

On Thu, May 25, 2017 at 6:00 PM, Emily Youcha <ekyoucha@alaska.edu> wrote:

Yes, I am sure. Case temperature is required for the measurement according to everything I read and the campbell manual for the eppley pir. Dome temperature can be used also for a correction, but not required. I checked with Busey and he doesn't use dome temp at all. But we can wire it in also though and read more about it:

See description:

http://www.eppleylab.com/instrument-list/precision-infared-radiometer/ Model PIR

The Precision Infrared Radiometer, Pyrgeometer, is intended for unidirectional operation in the measurement, separately, of downwelling or upwelling longwave irradiance. Unlike instruments that measure the shortwave (short) irradiance, there is no official ISO/WMO classification of pyrgeometers which are designed to measure the longwave (infrared) irradiance from the sky. The PIR comprises the same wirewound thermopile detector and temperature compensation circuitry as found in the SPP pyranometers. This thermopile detector is used to measure the “net radiation” of the PIR and a case thermistor (YSI 44031) is used to determine the outgoing radiation from the case. A dome thermistor is also included if one wishes to measure the dome temperature as compared to the case temperature to make any “corrections” to the final result.

On Thu, May 25, 2017 at 5:10 PM, Robert Gieck <regieck@alaska.edu> wrote: Are you sure about the dome temperature. That is what you are comparing the surface temp to not the case temp....rob

On Thu, May 25, 2017 at 3:50 PM, Emily Youcha <ekyoucha@alaska.edu> wrote: That is a good idea to have a badge I suppose.

We have to remake the radiation cables, the case thermistor wasn't wired up (Pin D and E) for the PIRs. Needs case temperature (required) and dome temp (F and G) is optional, but we might as well include dome temp. I am going to order some more connectors and then make up a bunch and one of us will drive up for a 1 day trip sometime in early June I guess. 

 Potential PIR CR1000 Programming Mistakes (Ken)
  • Upon reviewing an old program for FBmet I noticed the PIRs program was using "dome temperature" (ex: "TLW_dome" and "ALW_dome") and using the "panel Temperature" ? as the thermocouple reference. Case temperature should have been used, which would have been a thermistor in the PIR.
    • public rad_mV(MUX1_QTY)
    • alias rad_mV(1) = TLW_mV
    • alias rad_mV(2) = ALW_mV
    • alias rad_mV(3) = ISW_mV
    • alias rad_mV(4) = RSW_mV
    • Alias rad_mV(5) = Net_rad
    • Public radiation(MUX1_QTY)
    • Units radiation() = wpm2
    • Alias radiation(1) = TLW
    • Alias radiation(2) = ALW
    • Alias radiation(3) = ISW
    • Alias radiation(4) = RSW
    • 'alias radiation(5) = Net
    • Public tc(2)
    • Units tc() = degC
    • 'Units tc(2) = degC
    • Alias tc(1) = TLW_dome
    • Alias tc(2) = ALW_dome
    • sub read_mux1()
    • MUX1 has 5 radiometers, 2 thermocouples, 1 pressure transducer,
    • and a 10:1 voltage divider
    • PortSet(MUX1_ENABLE_PORT, 1)
    • terrestrial long wave radiation
    • PulsePort(MUX_CLOCK_PORT ,MUX_CLOCK_PULSE)
    • VoltDiff(TLW,1,mv25,MUX1_DE,1,0,250,TLW_MULT,0)
    • atmospheric long wave radiation
    • PulsePort(MUX_CLOCK_PORT ,MUX_CLOCK_PULSE)
    • VoltDiff(ALW,1,mv25,MUX1_DE,1,0,250,ALW_MULT,0)
    • incident short wave radiation
    • PulsePort(MUX_CLOCK_PORT ,MUX_CLOCK_PULSE)
    • VoltDiff(ISW,1,mv25,MUX1_DE,1,0,250,ISW_MULT,0)
    • reflected short wave radiation
    • PulsePort(MUX_CLOCK_PORT ,MUX_CLOCK_PULSE)
    • VoltDiff(RSW,1,mv25,MUX1_DE,1,0,250,RSW_MULT,0)
    • net radiation
    • PulsePort(MUX_CLOCK_PORT ,MUX_CLOCK_PULSE)
    • VoltDiff(Net_rad,1,mv25,NET_DE,True,0,250,1000/NET_MULT,0)
    • If WS_3m>=5 Then
    • Net_rad=Net_rad*(1+0.021286*(WS_3m-5))
    • Else
    • Net_rad=Net_rad
    • EndIf
    • IMPORTANT: thermocouple reference temperature is currently
    • set to use logger panel temp, but this assumes that the
    • multiplexer is in the same enclosure with the same temperature
    • environment and gradients.
    • measure radiometer thermocouples:
    • PulsePort(MUX_CLOCK_PORT ,MUX_CLOCK_PULSE)
    • TCDiff (tc(1),1,mV2_5C,MUX1_DE,TypeT,panelT,1,0,250,1.0,0)
    • PulsePort(MUX_CLOCK_PORT ,MUX_CLOCK_PULSE)
    • TCDiff (tc(2),1,mV2_5C,MUX1_DE,TypeT,panelT,1,0,250,1.0,0)
    • PortSet(MUX1_ENABLE_PORT, 0)
    • EndSub ' read_mux1
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