Relitive Humidity measurement

Stevezila

Hello, I'n looking for an effective·way to measure the relative humidity in a given space over a period of time, 24hr. and sending·the info·to a data logger for evaluation and charting at a later date. I have done it with temperature and it works well but now I need to account for humidity. I am not aware of a good relative huminidty sensor. Please advise!

Tracy Allen

Parallax sensor item 28018 is an SHT11 temperature/humidity sensor with digital interface, quite accurate. Item 27920 is a cheaper sensor that would need more interface and calibration.

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Tracy Allen
www.emesystems.com

WBA Consulting

The SHT11 sensor that Tracy mentions is ideal for logging accurate temp and humidity readings from a single device. It is very stable and it's accuracy/ease of use combination isn't currently matched by anything else out there now. I have used the SHT11 sensor with the stamp and logged temp and humidity data.

Not sure which data storage method you are using, but here is a link to my BS2P40 Plungelogger that used a VMusic2 module. The VMusic2 module uses the same code format as Parallax's 27937 Memory Stick Datalogger. Here's a link to BS2 code that reads two SHT11 sensors and displays it on an LCD.

I have since moved to the Propeller and have the same project, but now log directly to SD cards. For this year's plunge, I am also modifying a pocket sized display unit that will read the data off the SD card and graph results on a 2" display, so I can get immediate, detailed results without a computer.

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Andrew Williams
WBA Consulting
WBA-TH1M Sensirion SHT11 Module
Special Olympics Polar Bear Plunge, Mar 20, 2010
Propeller-Based Reverse Geo-Cache Birthday Present Project

Post Edited (WBA Consulting) : 2/23/2010 11:55:50 PM GMT