Related
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

HRM Tri malfunctioning after open water swim

Salvador
over 3 years ago

I have a forerunner 735xt. Never had an issue with the hrm Tri so far, until lately that has started giving me erratic data. For example, the number of calories burnt are way too low, the times spent in heart zones are totally incorrect too and sometimes the distance covered is very incorrect. I swim almost every day, covering the same distance, so I know pretty much the data I should be getting. However, all goes wrong lately. I don’t have a problem when I go running or cycling with the strap, it’s only after open water I get this.

is there a way I can sort this out? How can I check the software version of the hrm Tri strap? Could it be a matter of an update? My watch has the latest software version, 9.80.

Thanks

  • 0 over 3 years ago
    Salvador said:
    the number of calories burnt are way too low, the times spent in heart zones are totally incorrect too

    These are data calculated by the watch based on heart rate data comming from the strap. If heart rate comming from the HRM Tri is incorrect, then perhaps the strap is worn out and should be replaced. These things do deteriorate with time and use....

    Salvador said:
    and sometimes the distance covered is very incorrect

    This has nothing to do with the HRM Tri.

    Salvador said:
    How can I check the software version of the hrm Tri strap?

    Make sure the strap is connected to the watch and go to sensor settings. There you'll find all the strap details, including firmware version.

    Salvador said:
    Could it be a matter of an update?

    Unlikely. There's been no update to the HRM-Tri for several years.

  • 0 over 3 years ago in reply to tmk2

    Thank you! I still have one question though: If for any reason the strap stops working, the heart rate is picked automatically by the wrist sensor. Is that right? If so, I really don’t get why those gaps appear in the graph below. This is a graph of the heart rates of my bicycle ride today. While I was on the bicycle, I saw my watch and noticed that the field of the heart rates on my screen was blank at some points. 

  • 0 over 3 years ago in reply to Salvador
    Salvador said:
    If for any reason the strap stops working, the heart rate is picked automatically by the wrist sensor. Is that right?

    If the sensor really stops working then yes, after a while the optical sensor should kick in. BUT! It is possible, that the sensor stays connected, and still sends other data, like for example the running dynamics, i.e. it DOES NOT switch off entirely, but for some reason does not give any heart rate reading, possibly due to degraded electrode contact. Just a hypothesis...

  • 0 over 3 years ago in reply to tmk2

    Thinking Looks possible. Anyway, I will have it tested again today and see how it goes. It could also be that the battery will need replacement soon, although I still don’t get the warning on the watch screen and its status is still OK. Thanks again, your answers are always enlightening. 

  • 0 over 3 years ago in reply to tmk2

    Ok, this is the graph after this morning open water swim. I swim pretty much the same distance every day, at the same pace, so I know the data I should be getting at the end. This is the graph of the heart rates. Again, you see a sudden drop, as if the sensor stops to work and then it wakes up again. As a result of that, all my data at the end are wrong: calories, time spent in heart rate zones, etc. I am just trying to figure out wether this is due to a faulty HRM tri sensor, or it’s just the battery about to die? I still get no battery warning on the watch though..