What is a quick temperature sensor

Hi,

I my project I need to have 2 temperature sensors. One sensor to act as a reference temperature and the other as the ambient temperature sensor.

I am currently using 2 DS18B20.

Using the DS18B20 as the reference sensor is totally ok as it just needs to record the temperature in a sealed environment however the DS18B20 is not very fast at reacting to ambient temperature sensing.

Is there a better temp sensor that is very quick at registering temp changes. For example opening a fridge door and holding the sensor in your hand your place your hand into the fridge and then pull it out and it registers the change a lot more quickly than the DS18D20 does.

Thanks

The lower the mass of the sensor, the faster it can respond. Try a thermocouple. Can't get less mass than that.

Google "thin film thermistor"

I've got some thermistors with lead wires so thin that they are almost invisible to the naked eye. Thinner than a hair; smaller than any thermocouple I've seen. That has a fairly good response to rapid changes in air temperature. I forget where I got them or the part number.

An IR thermometer can have a faster response as it's measuring the temperature of things, not its own temperature.

MorganS: An IR thermometer can have a faster response as it's measuring the temperature of things, not its own temperature.

Agreed, but I do not think they work on air. I read the OP as measuring air temperature and not the temperature of an item.

Thanks all for your great replies.

I have decided to go with a couple of thermistors to do my measuring of air temps.

thanks

Forced airflow will accelerate temperature response speed dramatically in air, and much more importantly
reduce the effects of IR heat radiation which is very noticable(*) with plastic bodied sensors like the
DS18B20 TO92 package.

Using a metal bodied/encapsulated sensor rejects heat radiation pretty efficiently too.

  • expect several degrees error from this if you are near the sensor from your body heat radiation.

There are different sensors like DHT, SMT, DS18 etc but these sensors are slow and provide fluctuated valures sometime, I would recommend you to use these I2C compatible sensors like SHT 31, SHT25, HIH6130 and many others , these are accurate , reliable and even have different mode of operations

MarkT:

  • expect several degrees error from this if you are near the sensor from your body heat radiation.

Have you measured this? Are you sure that it was heat radiation and not convection?