|Cateye HRM/computer questions and problems?||Bosephus|
Jul 9, 2002 8:02 AM
|Can somenoe out there explain the science behind how a HRM picks up the signal from your heart? I know how it sends the signal and all that ... I'm just a little fuzzy on the initial signal acquisition.
I'm having problems with a Cateye HRM/Computer giving me false readings and I have a theory why but it depends on how the thing actually acquires its original signal. Is it vibration based?
It basically gets in this weird mode where it won't read fluctuations in my heart rate unless I hold it super tight against my chest. It just sticks at around 162 even when I stop pedalling and just coast ... if I manually check my heart rate it will be down in the 120 range. I've changed the batteries and that didn't help. Anyone else have this problem with an HRM?
Jul 9, 2002 8:16 AM
|The HRM reads electrical impluses from the skin. The chest strap has to wet with sweat, saliva, or the special conductive cream that can be purchased for use with HRMs.
The sensor also has to be in tight contact with the skin.
If you read the instructions, it says that the electrodes on the chest piece wear out. I've had them last as little as 1 year before they quit. New electrodes can be purchased from Cateye distributors or your LBS, but not directly from Cateye (they don't sell to the public).
Some other brands of transmitters will work with the Cateye HRMs (but not Polars which have coded signals).
The signal can be affecteed by electrical lines and other radio transmissions. I have certain areas of my regular route where the HRM always quits working do to interference.
Jul 9, 2002 8:24 AM
|Ok ... this generally starts happening well into my ride ... after I'm pretty sweaty, so conductivity shouldn't be a problem. WHich part is the sensor? The little black pads?|
Jul 9, 2002 12:59 PM
|Should have said electrode pads rather than sensors and yes it't the black pads on both sides of the chest transmitter.
Be sure that you aren't close to overhead electrical lines or some source of strong radio transmission when the problem occurs. Like I said, mine craps out several times on each ride due to interfering signals.