ONRHYTHM 310 watch and belt with heart rate monitor blue



Made for athletes who want to measure their heart rate to manage their effort.
All the indicators you need to manage your workout. Its coded signal prevents cross-references with other HRM devices.

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Parameter measurementStopwatch, heart rate (BPM and %HRmax), calorie and fat expenditure.
Ease of useCoded analogue transmission: no crosstalk with surrounding monitors
WaterproofWatch: 5 ATM (swimming) - Chest strap: 1 ATM (water splashes).
CoachingTarget zones: Heart rate (BPM or %HRmax), kcal.
Warranty2 Years
Technical Information

Measurement set-up
Stopwatch, heart rate (BPM and %HRmax), instant and total calorie expenditure, burnt fat (grams)
Target zones
You can set up target zones for a better management of your training. It shows you, in real time, whether you are within the target zone you have set up. The ONrhythm 310 access features a mode that lets you set up heart rate target zones (BPM or %HRmax) and calorie expenditure target zones (kcal/h)
Time, date, alarm, backlight
Heart rate monitor
The coded signal (5.3kHz) avoids crosstalk with other heart rate monitors when practising in a gym or with a group.
Latest session display.
Compatible with Gcoded HW cardio belts (included).
Watch: CR2032 included - Belt: CR2032 included
Watch: 5 ATM (swimming) - Chest strap: 1ATM (water splashes)
Pack content
ONrhythm 310 access HRM watch + plastic Gcoded chest strap + instruction leaflet
Information / Concept / Technology
Wrist : 90.0% Polyurethane (PU), Wrist : 10.0% Stainless steel Structure : 70.0% Polycarbonate - Acrylonitrile Butadiene Styrene (PC-ABS), Structure : 30.0% Stainless steel Inside room : 100.0% Printed Circuit Board Lens : 100.0% Polymethyl Methacrylate (PMMA)


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Lost signal issues due to persperation
Used for 2 to 8 weeks
I have had this device for a few weeks and the "Parrot" system in my car was always making it bleep. Very distracting !
Then within a dew weeks I had to change the chest battery and found that the battery was corroded. I guess due to personal 'persperation' at the gymnasium.
The O ring seating is not so clever and despite changing the battery in the chest band the wrist device is informing me that there is 'No Signal' ,,,, more often than not.
It is a pity as it worked well for about a month.
My local store in Tenerife were apologetic .......but ......
Response of the brand
Hi Mike,

Firstly I am sorry for the problems that you have had with your OnRhythm310 Heart Rate Monitor.

Given that the signal was working well and has deteriorated since the battery corroded I believe that the problem is linked to this and that the chest belt is not drawing enough power.

Unfortunately I have no authority over the store in Tenerife but if you are able to return it in the UK then you will have no problem.  You can let them know that you have been in contact with the UK Market Manager and that I believe that, given you have tried a new battery and that this has not rectified the problem that there is  a manufacturing problem that has led to the corrosion and that we should exchange the belt for you.

If it helps reply to my message and I can try to contact someone in the Tenerife store for you.

Kind regards,

David Daker
Market Manager Nutrition,
Electronics and Accessories,
no connectivity
It looses connectivity very often during traning. It is very frustrating.
Response of the brand
Hello Kristaq,

You have my sincere apologies for the poor functioning of your OnRhythm 310 Heart Rate Monitor.  The connection problem is know and the advice of the product manager for people with a watch that has these connectivity issues is to return it and replace with the new model where these issues have been resolved.  The replacement model is the OnRhythm 500. 


Please make it clear to the store team or to our customer loyalty team that your watch is defective and that I've recommended that we replace it for you with the new model. 

Kind regards, 

David Daker
Market Manager Nutrition,
Electronics and Accessories,
Kristaq found this answer helpful
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