Two Simple Ways of Measuring Temperature With Your Multimeter

One of the electronic gadgets that has made my life easier around home and on the work-site is the fluke multimeter. Whilst they’re mainly used by electricians in their day to day jobs, I decided to buy one to help me check if wires were live when I needed to work near them. It would be a disaster if I were to cut through a live wire with a circular saw! There are many, many different brands of multimeters on the market and some range from as little as $50 right up into the $500 ranges. You want to make sure you get the right one to suit your needs, so I recommend reading some guides before making your purchase. There’s a great guide, with what you should look out for here: http://www.themultimeterguide.com/

Far from that, I write this article with the aim of informing you on how to measure temperature with a multimeter. Not all meters have the ability to measure the temperature. I personally have the Fluke 87V, it’s one of the top of the range multimeters you can buy.

Why would you want to measure temperature? Here are just a few ways I’ve used my meter to take temperature readings in the past:

Recording temperatures of a water pump at my house, to see if it was over heating.
Logging the ambient air temperature over the seasons.
Used when working with a friend who does HVAC work, to test how fast a room cooled down.

The first way to measure temperature, if that functionality doesn’t come as standard on your meter, involves interfacing a temperature sensor to your test probes. You will have to create a small circuit, with some resistors and a TMP35 temperature sensor and then take your multimeter apart and carefully place it inside. Once you’ve done this, you simply select the millivolts setting on the dial and take the reading. If the reading is 335 millivolts, then you have 33.5 degrees Celsius. The TMP35 is set to Celsius, so you will need to do some converting if you wish to know the degrees in Fahrenheit. The guys at Instructables have written up a great step by step article that will show you how to do this method. Instructables Article

multimeter-temperature-sensor — The TMP35 Temperature Sensor

The other, much easier way to measure temperature with your multimeter is by using a meter which has temperature measuring capabilities already built in. You simply plug in the thermocouple adapter, switch the dial to temperature and start measuring. To select between Fahrenheit and Celsius, press the range button.