View Full Version : Humidity sensors

07-18-2006, 06:49 AM
Hi everyone,
I am working on a project to perform multi-channel data logging from sensors. The hardware as well as the software is nearly complete and i have already interfaced a temerature sensor to it. But i also need to design a proper interfacing circuit for sensing humidity, pressure etc.
Can you tell me which type of humidity sensors will be available in delhi and what would they cost like and where could I get them from.
Similar info on pressure sensors is also welcome but the humidty sensing is really an important factor in its proposed application.
So please help! :-)


07-21-2006, 12:46 PM
if accuracy is not your concern then i think with some commonly available objects around we can make a nice humidity sensor :D Just think around and you will get a plenty of ideas :)

07-21-2006, 02:04 PM
i dont know about humidity sensors,but freescale offers you a wiide range of pressure sensors.- check www.freescale.com . There are lots of them in different packages, and my presonal favourite is MPX5050 whichi used for a blood pressure meter. Go for the compensated ones.

07-21-2006, 03:25 PM
Basically, a Humidity sensor is a moisture sensitive capacitor.

Honeywell and Sensirion Humidity sensors are available through Farnell-in-one and RS components - abt 1500/- and above.

07-22-2006, 09:47 AM
Thank everyone for your replies,
Thanks docel: I'll call those people up and enquire furthur. The cost shouldn't be a problem if those people approve the puchase. The person under whom i'm doing my training had also hinted similar range, but had asked me to find out.
Thanks allbits: The info about pressure sensors was also useful. Are they sensitive enough to detect tappings with a drumsticks? I am trying to build a drumset for my PC:) if i learn more about audio processing, mixing etc. on UControllers, then I plan to make a standalone version as well.
Thanks devpriya: I'll twist my mind and tinker with stuff a little bit :idea: :!: :?:
Thanks everyone!!

07-22-2006, 02:50 PM
Are they sensitive enough to detect tappings with a drumsticks?

Yes they have sensors sensitive enough. Try the parametric search.
MPX 5050 or 2050 can easily detect the variation in blood pulses, so sensitivity may not be a problem.
Now, if you just want to detect if there is a beat on the drum, i think pressure sensors are not required. The packages of these sensors are small, so interfacing to the drum might be a problem.

all the best!!!

07-22-2006, 02:52 PM
forgot to tell ya.. didi you visit www.sensata.com ?? the sensor development wing of texas are a new company now!! you will find lot of them sensors.

07-23-2006, 12:17 AM
Use a Piezo buzzer element, stuck to a large diaphragm. It is sensitive enough for a whisper, will be quite sensitive to a tap of the drumstick!!!

]Another idea is to use a large dia speaker with a tight-drawn skin.

Both are sensitive enough and perform well with ADSR and BP filters.

07-23-2006, 05:31 PM
Thanks for the replies. Now I have plenty to ideas to help me in my projects.

02-13-2008, 10:47 PM
Just stumbled upon this link in my desperation to find a solution to my problem and I realised id registered on this site ages back!

Coming back to my problem.

I am in need of humidity, soil mositure and light sensors that give a voltage response for the variation in the condition hey are sensing. I have been able to make a soil moisture sensor (stil under testing) and trying to modify the light sensor as I only have access to LDR and no photocells.

I have no clue on how to get humidty sensor ICs (Honeywell has HIH3610 and HIH3605 and a few more ICs) but they are not available in Bangalore. I am unable to get the links u guys mentioned could u pls post the link here.

Pls reply asap. I need them urgently!!!

Thanks a ton