Polar T31 Coded Chest Transmitter and Elastic Strap – Black

Excellent Telemetry Strap. I purchased this telemetry strap to use while working out at the gym. Almost all the cardio machines at my gym have Polar receivers and can display my heart rate from this transmitter without having to hold on to the physical sensors. This may not seem like a big win, but it’s much more comfortable to walk on a treadmill or use an elliptical machine without having to hold on to heart rate sensors.Using the strap is easy: you just wrap it around your chest, connect the loose end of the strap to the sensor and moisten the contacts. There is no on/off button so you don’t have to worry about anything except for putting it on. It is fairly comfortable to wear, and I don’t really notice when it is on. The whole thing is made out of plastic and the strap is elastic. The build quality is excellent and it is completely waterproof.The strap is ‘coded’ which means that you don’t have to worry about interference from other people wearing straps around the gym. This works with the polar wrist-watches, but I have found that the ‘coding’ doesn’t work with the Life Fitness treadmills/elliptical machines or the Precor elliptical machines at my gym. Your mileage may vary, but if the person next to me on the machine is also wearing a telemetry strap, the machine will get confused and vary wildly in its reading. Sometimes it will display my heart rate, and others it will display the person next to me. This is more a problem of the proximity of the machines. If the other person is one machine away, there is no problem with interference. I haven’t found this to be a big deal, if I need to I just move one machine over.Pros:+ Fully waterproof+ Excellent build quality+ Comfortable+ AccurateCons:- Interference with other transmitters nearby in gym (this is a problem with the receiver on the equipment, not the strap).Bottom Line: Excellent strap to use with a watch. If you are using in a gym with a receiver on a machine, be prepared to deal with some interference if there is another transmitter within 5-10 feet.

2 year battery life BUT read the whole review. I bought this “NEW” in June of 2016. In July 2018 it started not broadcasting my heart rate for about the first 20 minutes every workout until it gets warm and a little sweaty, then it starts working, slowly coming down from 220 indicated BPM or so to what my actual heart rate is. (my heart doesn’t go 220-bpm) There are 25 spinning bikes in the room, it does the same thing ON ALL 25 BIKES, EVERY SINGLE BIKE SAME THING, so it is not the heart rate indicator on “THE BIKE”! I have used Polar HRMs since the 1990s maybe 1980s? Within the last 5 or 10 years or so the battery life has gotten shorter and shorter. Maybe mine sat on the shelf in some department store or in some bike shop for the first 5 or 10 years of its life before I bought it “NEW” from Amazon? I honestly don’t know what to do. I have to buy another one because all the equipment i use at the health club (where i work) is Polar compatible. Maybe the non-coded one is cheaper and will last longer, we will see.This is a follow up, March 2019. I tried an experiment for the last month or two. I run the transmitter under water in the sink at the health club for a second or 2, just to make it wet. I put it on wet and i go into the spinning room and it works perfectly the second i turn on the heart rate indicator on the bike. All the way through the workout it works perfectly. SO if you have one that stopped working or works intermittently, run it under water and put it on to see if that makes it work. Maybe it is an indicator that the battery is getting low but this saved me from buying a new one at this time. Good luck!

so far so good. I have an ft4, had for 8 years, original chest strap. Change the battery and away you go. Couple of weeks ago, wouldn’t pair, changed all batteries, nada. new set up $250 at least. not interested in ‘charge your watch every 7 days’. found this on Amazon, $49. took a chance. Seems to be working well. So fingers crossed, and if it continues to work, happy days.

It did not work when riding my bike. I had this transmitter before and really liked it. So I bought it again. It worked great on all the gym equipment. When I got on my mountain bike, it would “0” out when riding. If I brought my hand back about 5 inches, the watch would pick up the transmitter. So riding uphill with both hands on my handlebars it would not work. I contacted Polar about that and after no response from them, I just bought another unit. They had been good before on responding, not sure what is going on now.

Poor battery life. Purchased the Polar T31 on November 17, 2023, on December 29, 2023 it stopped working after four uses. I was curious if there was a malfunction with the unit or was it the battery. I dismantled the unit knowing I wasn’t going to send it back and checked the battery. The 2023 battery is rated at 3 volts, the battery in my T31 is only putting out .85 volts. Not enough to transmit a signal to my treadmill.I come to the conclusion the Polar T31 I was sold had to be “new old stock”.I do not recommend this product!!