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HMP 60 Wrong RH


Leel Dec 13, 2011 03:17 AM

Hi All,
My RH value is wrong (its in decimals) .Reading are attached.
Please help me to correct it.

NO TEM RH DATE TIME RECRDAIR BARO A.WIND WINDStDev Rain
PRESS SPEED DIR WD
"2011-11-27 10:00:00",5468,31.4,0.409,1008.207,2.555,40.13,16,0
"2011-11-27 10:30:00",5469,32.16,0.477,1008.336,2.632,56.84,35.45,0
"2011-11-27 11:00:00",5470,33.08,0.409,1007.87,2.731,55.97,26.66,0
"2011-11-27 11:30:00",5471,33.46,0.409,1007.707,3.247,37.32,13.95,0
"2011-11-27 12:00:00",5472,33.31,0.477,1007.543,2.426,79.99,35.28,0
"2011-11-27 12:30:00",5473,33.73,0.477,1006.993,2.434,71.17,25.98,0.2
"2011-11-27 13:00:00",5474,34.47,0.477,1006.313,2.715,55.04,17.46,0
"2011-11-27 13:30:00",5475,34.38,0.477,1005.986,2.625,67.15,31.33,0
"2011-11-27 14:00:00",5476,34.62,0.409,1005.495,3.527,36.69,10.83,0
"2011-11-27 14:30:00",5477,33.45,0.409,1005.093,3.06,38.87,12.73,0
"2011-11-27 15:00:00",5478,32.42,0.409,1004.935,2.637,38.39,11.17,0
"2011-11-27 15:30:00",5479,30.97,0.409,1004.652,1.524,66.69,27.03,0
"2011-11-27 16:00:00",5480,30.06,0.409,1005.011,1.869,77.86,22.91,0
"2011-11-27 16:30:00",5481,29.72,0.409,1005.089,2.407,57.68,16.73,0
"2011-11-27 17:00:00",5482,29.39,0.409,1005.435,2.142,59.83,14.96,0
"2011-11-27 17:30:00",5483,28.71,0.409,1005.435,1.937,59.93,13.73,0


ChipsNSalsa Dec 15, 2011 10:06 PM

What multiplier are you using in the VoltSE instruction that's measuring the RH portion of the HMP60? The manual says 0.1 for percent and 0.001 for fractional (like your decimal RH).


Leel Dec 19, 2011 09:29 AM

Thanks.

But the multiplier is set as 0.1

Please find the program.

CR1000 Series Datalogger

'-------------------------------
' Program Name : Piyadasa.CR1
' Date : February 13, 2006
' Author : Simon Leeds, CSA
'-------------------------------

'Declare Constants
Const BucketSize = 0.1 ' Tipping Bucket Rain gauge bucket size (mm per tip).

'-------------------------------

'Declare Public Variables

Public Air_Temp
Public RH
Public Baro_Press
Public Rain_Int
Public Wind_Speed
Public WindS_Kph
Public WindS_knots
Public Wind_Dir
Public Baro_Meas as Boolean
Public Flag(8) as Boolean

Units Air_Temp = degreesC
Units RH = %
Units Baro_Press = millibars
Units Wind_Speed = mpersec
Units Wind_Dir = degrees

'-------------------------------

'Declare Other Variables

'-------------------------------

'Define Data Tables
DataTable(Thirty,TRUE,-1)
DataInterval(0,30,min,15)
CardOut(0,-1)
Average(1,Air_Temp,FP2,0)
Sample(1,RH,FP2)
Sample(1,Baro_Press,IEEE4)
WindVector(1,Wind_Speed,Wind_Dir,FP2,0,0,0,0)
FieldNames ("Avg_WS:, Avg_WD:, StDev_WD:")
Totalize(1,Rain_Int,FP2,0)
EndTable

' Daily Storage.
DataTable(Daily,TRUE,-1)
DataInterval(0,1440,min,10)
CardOut(0,-1)
Average(1,Air_Temp,FP2,0)
Maximum(1,Air_Temp,FP2,0,0)
Minimum(1,Air_Temp,FP2,0,0)
Average(1,RH,FP2,0)
Maximum(1,RH,FP2,0,0)
Minimum(1,RH,FP2,0,0)
Average(1,Baro_Press,IEEE4,0)
Maximum(1,Baro_Press,FP2,0,0)
Minimum(1,Baro_Press,FP2,0,0)
WindVector(1,Wind_Speed,Wind_Dir,FP2,0,0,0,0)
FieldNames ("Avg_WS:, Avg_WD:, StDev_WD:")
Totalize(1,Rain_Int,FP2,0)
EndTable

' Event based rainfall storage.
DataTable(Rainfall,TRUE,25000)
CardOut(0,250000)
Sample(1,Rain_Int,FP2)
EndTable

'-------------------------------

'Define Subroutines

'-------------------------------

' WIRING LIST
'-------------

' HMP50 Air Temperature and Relative Humidity
'--------------------------------------------
' Black - SE1 (Temperature)
' White - SE2 (RH)
' Blue - G (Signal and Power Reference)
' Brown - SW12V (Power)
' Clear - G (Shield)

' 03001 Wind Speed and Direction
'--------------------------------
' Wind Speed
'------------
' Black - P1
' White - G
' Clear - G
'
' Wind Direction
'----------------
' Black - EX1
' Red - SE3
' White - G
' Clear - G

' CS105 Barometric Pressure Sensor
'----------------------------------
' Blue - SE4 (Pressure Signal)
' Yellow - AG (Signal Ground)
' Red - 12V (Power)
' Black - G (Power Ground)
' Green - C1 (Power Trigger)
' Clear - G (Shield)

' TE525 Rain gauge
'------------------
' Wire 1 - P2
' Wire 2 - G

'Main Program

BeginProg

Scan (10,Sec,0,0)

'- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
' Every 15 minutes, indicate we need to measure the CS105 (Barometric Pressure Sensor).
If IfTime(0,15,min) then
Baro_Meas = True
EndIf
'- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
' Turn on the HMP50 (Air Temperature and Relative Humidity sensor).
SW12 (1)
' If the time is right, turn the Barometric Pressure sensor ON.
If Baro_Meas then
PortSet(1,1)
EndIf
' Wait for the HMP50 and CS105 sensors to warm up (1 second).
Delay(0,1,sec)
'- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
' Measure the sensor outputs.
' Air Temperature.
VoltSe (Air_Temp,1,mV2500,1,1,0,250,0.1,-40)
' Relative Humidity.
VoltSe (RH,1,mV2500,2,1,0,250,0.1,0)
' Turn the HMP50 OFF.
SW12(0)
' If it is time, measure the Barometric Pressure sensor and then turn it off.
If Baro_Meas then
VoltSe (Baro_Press,1,mV2500,4,3,0,250,0.184,600)
Baro_Meas = False
PortSet(1,0)
EndIf
'- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
' Measure the wind speed and direction sensor.
' Wind Speed (03001 - convert to Hz to m/s by using multiplier = 0.75, Offset = 0.2)
PulseCount (Wind_Speed,1,1,1,1,0.75,0.2)
If Wind_Speed = 0.2 then Wind_Speed = 0
'Convert Wind Speed to kilometers per hour
WindS_Kph=Wind_Speed*3.6
'Convert Wind Speed to knots
WindS_knots=Wind_Speed*1.9425

' Wind Direction (Instruction output is Vs/Vf. USe multiplier of 355 to convert to degrees).
BrHalf (Wind_Dir,1,mV2500,3,Vx1,1,2500,True ,0,250,355,0)
'- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
' Count tips on the rain gauge.
PulseCount (Rain_Int,1,2,2,0,Bucketsize,0)
' Store event based rainfall data if we had a rain bucket tip.
If Rain_Int then
CallTable Rainfall
EndIf
'- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
' Call Data Tables - 30 minutes.
CallTable Thirty
'- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
' Call Data Tables - 24 hours.
CallTable Daily
'- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

NextScan

EndProg


aps Dec 19, 2011 10:20 AM

Program looks OK. One other thing to try, Vaisala specify a 2-4 second delay for that probe, which is longer than the 1 sec delay for the HMP50.

Try increasing the delay to 4 seconds. Delay(0,1,sec) -> Delay(0,4,sec)

If you still get the low readings check the connections, looking for a short and then if you have the equipement check the setup of the probe itself (the HMP60 is programmable so the output could be switched off).

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