Author Topic: Vaisala INTERCAP humidity sensor as replacement for analog temp/hum board  (Read 32 times)

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Offline CW7491

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I learned from a member here that the Vaisala HUMICAP180R will work with the old analog Davis temp/hum board. These sensors are the same sensor used in all of the top of the line humidity sensors from Vaisala. While the sensor does work with the Davis, according to Vaisala, the capacitance readings are slightly different from their INTERCAP sensor which uses the exact same chip, but is significantly cheaper ($77 v $161).

After doing some research, I found that Davis actually used to put in their product manuals the option of using a Vaisala HUMITTER temp/hum sensor. The HUMITTER probe used Vaisala's INTERCAP sensor. I've tried both and the HUMICAP reaches 100% humidity, but tends to have a wet bias at dry humidity (same or maybe even a little worse than Sensirion). The INTERCAP on the other hand performs extremely well. It reaches 100% humidity and performs well at low humidity. I've asked Davis and Vaisala if Vaisala produced the original Davis humidity element and neither would confirm, but that is my suspicion.

I've placed the INTERCAP in the same shield side by side with the current Davis digital sensor and it confirms what has already been commented on: the Sensirion sensor reads about 3-8% high below about 40-45% humidity and the Sensirion gets "tight" at high humidity and reports 2-3% low above 80%.

For those of you who need or want to replace your humidity sensor with a Vaisala sensor and have the old analog sensor, the Vaisala INTERCAP is plug and play. There is finally a known replacement for failed humidity elements for the analog VP2. And as the technology and sensor element was the same as I understand it, it should work with the VP1 and WMII as well.
« Last Edit: Yesterday at 10:10:26 PM by CW7491 »

 

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