Polar HRM - no HR reading

[alpinerabbit]

I'm going nuts with my wearlink (the textile variety) polar. I hate it. It keeps telling me I'm dead. I had the batteries replaced last July, I believe they even gave me new straps. Paid good money for the rehaul.
The old, plastic one, you just have to get it a wee bit wet and it reads.

I haven't gotten round to calling them to complain, but I am seriously considering ditching it and getting some other brand.

[SuperRunt]

I did some more searching yesterday, and came across a post on another forum about a similar problem. This guy had washed both the electrodes on the Wear Link, and scrubbed the connections (the "buttons" on each side of the transmitter). So I washed the electrodes with dish soap, and used both soap and the dish brush to get into the connections.

I went skiing again this morning, and it worked!

A couple of other things I picked up:

1. Change of battery might help, even if the difference in new and old was only 0.33V.
2. Some jerseys are more staticy than others, and might cause problems with static electricity.

[OakLeaf]

Aloe vera gel works really well for me as an electrode gel. The pure stuff, without added oily moisturizers etc (which can interfere with contact).

I have a Garmin and don't know much about the peculiarities of Polar HRMs, but in mine, intermittent readings combined with max-out spikes happen when contact is poor. Cold weather (i.e. not much sweat) is a big culprit there, and that's where the gel helps a lot. But a sports bra that puts pressure on the strap in the wrong places can get in the way too, and so can too much sweat on very hot days.

If you're in a deep tuck on your bike it can also force the electrodes away from your body. The instructions on my Garmin say that some cyclists get better contact with the electrodes on their back.

I don't think you'd be getting the spikes if the battery was low. Easy way to check for a weak battery in a known good unit is to check the range of the transmitter. Put the strap on, hold the receiving unit close to your chest, and wait until you have a good reading. Then gradually move the unit to arm's length and see whether you still have a reading. Next, turn the unit off and on and see whether it will acquire a signal when it's held at arm's length (or a foot or so beyond arm's length). If it won't, or if it's particularly slow about it, then your transmitter battery is probably weak. Otherwise it's something else.

[GLC1968]

Another cause for reading problems - interference from something local. I have problems with both my headlight (in the winter) and with a few powerline locations. I also had a problem in this one spot near where I used to work that happened every single day for about 2 months, and then went away. I think they must have been doing some type of traffic reading or something that interfered temporarily? When I would hit that area, my HR would spike for a few seconds (in the 200s) and then I'd be 'dead' for about a minute. Once I rode out of the problem, the HR would return to normal.

In my case, I knew it was outside interference and not the unit because it would also affect my speed and cadence readings.

On your chest strap, it helps to rinse it with clear water and let it dry after each use. Salt (from sweat) build up will affect readings and a quick rinse helps keep that at bay.

[Mags...]

I've had intermittent problems with my polar HRM's (both CS200cad and RS200sd) from the start and have finally figured it out... If I wear a bra with underwire I get periods of no heart rate and also readings over 200... If I wear a sports bra with no underwire or a top with built-in bra (no wire) both HRM's work perfectly.
Also, if I wear the earphones for an mp3 player with cable running down the front of my shirt I get the same problems, if I wear the earphone cables running down my back - no problems with the HRM.