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New HMP155 Installation Issue


ND Rancher Mar 28, 2020 02:43 PM

Installed HMP155 w/CR1000X.  Fahrenheit temperatures and humidity seem to be accurate.  Centigrade temperatures indicate more than 20 degrees higher than expected.  Humidity registers in the 60%'s vs. more realistic mid-20's. Does not appear to be a calculation problem since, the time variances between Fahrenheit and Centigrade temperature versions oscillate much differently.  Checked wiring, again!  Example results: Ptemp_C=26.48 degs; AirTF=77.92 degs; AirTC=42.32 degs; RH=24.77%; RH_2=61.60%.

Created program with "Short Cut". 

measurement 'PTemp_C'
PanelTemp(PTemp_C,60)

Sensor measurements 'AirTF' and 'RH'
VoltSE(AirTF,1,mV1000,2,False,0,60,0.252,-112)
VoltSE(RH,1,mV1000,3,False,0,60,0.1,0)
If RH>100 And RH<108 Then RH=100

Sensor measurements 'AirTC' and 'RH_2'
VoltSE(AirTC,1,mV1000,5,False,0,60,0.14,-80)
VoltSE(RH_2,1,mV1000,6,False,0,60,0.1,0)
If RH_2>100 And RH_2<108 Then RH_2=100

Any insight would be welcomed!


ND Rancher Mar 30, 2020 08:57 AM

Made "Newbie" mistake!  Didn't realize "Short Cut" program might change wiring configuration after initial setup.  (I made some changes in the polling order.)  After correcting for this oversight, the results are now as expected.

I do have one additional issue..  I have set the HMP155 up to read the Centigrade temperature.  When I attempt to add the Fahrenheit temperature, "Short Cut" doesn't appear to allow the use of the same wiring scheme.  How do I address this problem, short of wiring terminals, together?

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