Topic: Davis Temperature Sensor Type - Looking to use IR sensor

[CPMaverick]

I am interested in buying a 6372 unit to add to a Vantage Pro2. The purpose would be to use an IR (infra-red) temp sensor with the 6372.

I can't seem to find the specification for the Davis temperature sensors, so I can source / build an IR sensor that is compatible.

Any help on either compatible IR sensors or the specs of base Davis temp sensors so I can source an IR sensor would be much appreciated!

[johnd]

The T/H input on VP2 SIM boards can accept 2 types of input:either from a digital T/H sensor or an analogue T sensor. The digital input is the old Sensirion not-quite-I2C protocol. But I guess you will be more interested in the analogue input, given that the (now-discontinued-as-a-bundle) 6372 was supplied with the 6470/6475 soil etc temperature-only sensor. (AFAIK the sensor is identical for 6470/6475 but 6470 has sturdier cable and bare-wire termination whereas 6475 has standard cable and fitted with RJ11 plug.)

6475 is a precision thermistor sensor. If you check out the specification/data sheet for 6470/6475 on the Davis website then you'll find a graph and table of resistance vs temp at Fig 1.

[CPMaverick]

Many thanks for that information!

Do you know what voltage output Davis uses for these thermistors? I don't see a voltage on the 6470 spec sheet, and most IR thermistors have a voltage range requirement.

[johnd]

Since the SIM board operates on a nominal 3v supply then I guess that is the voltage, but I'm not aware that the exact pin-out specs are published anywhere.