Calibrating the Foot Pod that Comes with the Polar S625X
I've been testing the Polar S625X Running Computer that includes a heart rate monitior and a Polar S1 Foot Pod that measures the speed and distance that you run. In my first test, I ran 5 kilometers as measured by my Garmin Forerunner 201, an GPS-based outdoor exercise computer that's also useful for running.
At the end of the run, the distance displayed by the Forerunner 201 was 3.16 miles while the Polar S625X showed 3.57 miles [ see the photo ]. I've run and cycled enough with the Forerunner 201 to know that I'm satisfied with the accuracy of the distances it measures, so I decided to calibrate the Polar S625X using the "manual calibration" method discussed in the Polar S625X user manual on page B38.
The manual calibration method is probably the best way to calibrate the Polar S625X in the middle of the winter, since the "calibration by running method" requires you to run a measured course of at least a quarter of a mile (about 400 meters) and many outdoor tracks in this part of the United States are buried under a foot or more of snow this week.
All I needed to do to perform a manual calibration was enter the ratio between the "actual" distance run and the distance measured by the Polar S625X. That ratio is 3160 / 3570 x 1000 or 885. I entered "885" on the Polar S625X display in the field for the calibration factor.
In my next test, I will probably repeat the 5 kilometer run with both the Polar S625X and the Garmin Forerunner 201 to see if the calibrated S625X measures the distance run almost exactly as the Forerunner 201 does.
Comments
I have been trying to decide between a Timex irone man which uses gps for distance measurement and the polar s625x which also measure's distance. I have been assured in terms of quality from several vendors that the polar s625x is in a class of it's own. I am however still trying to figure out exactly how the s1 footpod measures the distance without having any reference such as the GPS uses ?? Anybody help !!!
Posted by: Morne Botha | March 22, 2005 2:20 AM
The foot pod counts your strides and i guess works out from your stride what it needs to calibrate the distance,
I calibrated mine on a tredmill over a kilometre. It decided it had enough part the way through, I dont konw why.
My first run was about 700m short, 7 days later same training run, within two minutes time wise was a whole kilometre out, and the pace was all over the place.
Have just ried the above manual calibration and will see where this gets me.
I feel that the accuracy is spot on for those of us who a solid runners but for people like me who dont have much in the way of style it can be a varied affair?
Posted by: stuart | June 23, 2005 9:57 AM
I've done the manual calibartion as well. Although, after doing the calibration, I ran an exercise. In the wrist unit file shows 7.1 Km, but when I transfer the data to the PC, the same exercise shows 6.2 Km. What's wrong? Is any setting missing? Thanks!
Posted by: Marcio | January 28, 2007 7:52 PM