High sensitivity rapid response themistor

Hi guys

I need to build a air temperature sensor. I have the basic circuit worked out ... its just a wheatstome bridge. Trouble is that I need to find a suitable thermistor. I'm a bit of a newbie so sorry if I get some of the terms wrong.

It needs to be pretty sensitive ... sensitive to pick up say ay .1 degree change in temperature.

It also needs to have a low thermal time constant as I need it to respond in approx 3 to 5 seconds ... I've seen some but their thermal time constants are around 15 to 30 seconds which is way to slow.

It also needs to respond to air temperature rather than raditaion ... although I guess I could 'grind' off the glass on the glass bead evacuated types.

I'm told it will also need a high resistance such as 2MΩ in order to reduce current. A high current can cause the thermistor to heat up and any passing air can cool it down giving a false indication.

Any ideas?

Cheers

Mike

Take a look at this item:
**broken link removed**

... if the cost is not prohibitive.

Actually ... you might want to contact the support rep for the above company and see if they can suggest anything for your specific requirements.

Check that one: SHT11.

It measures temperature and relative humidity.

16bit A/D converter and serial interface are integrated. Response time 5 to 30 seconds.

Boncuk

Boncuk said:

Check that one: SHT11.

Click to expand...

Where can you buy it in small quantities?