HIH-4021 Readings Very High Outside

[SangamoWeather]

I have a newly built HT3-R1-A with the updated HIH-4021 humidity sensor. When I have it outside (in shade or at night) or even near an open window, I get readings of over 1000%. (As in 'one thousand percent' RH).

I used OneWireViewer to check readings at every second and also Tim Bitson's java program from WeatherToys reading every minute, but same deal with each. One exception with OWV, it seemed to fluctuate from very high to lower levels occassionally. Inside with windows closed, it comes back to acceptable levels.

I have also changed cables. Again, this happens even at night, which eliminates the sunlight factor.

Thank you in advance for your suggestions.

 

[ericvic]

I have a newly built HT3-R1-A with the updated HIH-4021 humidity sensor. When I have it outside (in shade or at night) or even near an open window, I get readings of over 1000%. (As in 'one thousand percent' RH).

I used OneWireViewer to check readings at every second and also Tim Bitson's java program from WeatherToys reading every minute, but same deal with each. One exception with OWV, it seemed to fluctuate from very high to lower levels occassionally. Inside with windows closed, it comes back to acceptable levels.

I have also changed cables. Again, this happens even at night, which eliminates the sunlight factor.

Thank you in advance for your suggestions.

That's very strange.

In the OWV can you look on the AtoD tab and tell me what the voltages are when it is reading 1000%?

Eric

 

[SangamoWeather]

Thanks Eric. I have it on OWV right now and it seems to be w/i accepted levels. I will get the data you requested as soon as it acts up.

Updated info, I was running it with the java program while I was at work this morning. Because the module was inside and shaded, it seems that the problem has nothing to do with being outside on near a windows as I suspected before.

Time = Fri Nov 05 11:45:00 CDT 2010
Temperature = 62.6°F
Humidity = 15052.813%
Dewpoint = 254.36606°F


Time = Fri Nov 05 11:46:00 CDT 2010
Temperature = 62.6°F
Humidity = 6007.866%
Dewpoint = 209.36671°F


Time = Fri Nov 05 11:47:00 CDT 2010
Temperature = 62.7125°F
Humidity = 3315.417%
Dewpoint = 183.31683°F


Time = Fri Nov 05 11:48:00 CDT 2010
Temperature = 63.5°F
Humidity = -9.526969%
Dewpoint = NaN°F


Time = Fri Nov 05 11:49:00 CDT 2010
Temperature = 63.8375°F
Humidity = 487.0387%
Dewpoint = 112.46832°F


Time = Fri Nov 05 11:50:00 CDT 2010
Temperature = 64.0625°F
Humidity = 651.2289%
Dewpoint = 122.66852°F

 

[SangamoWeather]

Eric: here is the info you requested.

AtoD:
Ch0 3.38-4.07V
Ch1 0.15V-10.04V
Ch2 0.0825-0.266V

When I first started OWV, the readings were within an accceptable RH range. I measured these voltages about 20 mins later when the RH began alternating b/t -5% and 100%.