14 September 2009-I decided to observe the barometer and altitude readings of my three ProTreks as they were affected by different temperatures. Checking the forecast last evening showed this morning would be ideal. Temperatures during test period times ranged from 50.F to 70.F appx.. Relative humidity ranged from 20 to 40 per cent appx.. Barometer fairly steady, gentle rising trend continuing since late yesterday. For records of a local station see:
Casio ProTrek models I used for observations:
PRG-100 module 3022
PRW-1300Y module 3070
PRW-1100YTJ module 3042
My actual home altitude measured by GPS is 4711 feet/ 1435.9 meters. In practice I use 4720 feet or 1435 meters to set my base altitude when I leave home and want altitude measurements. For the readings recorded today and listed below, I decided three days ago to remove all offsets and adjustments and set my three ProTreks to "OFF" for barometer and altitude. All three watches are set to Metric.
All watches were placed with the sensors upright during the resting times.
The first set of readings taken just before sunrise, the watches spent the night side-by-side on a window sill.
100= 0608h 18.1C 1018hPa 1420m
1300=0608h 18.3C 1018hPa 1440m
1100=0608h 18.2C 1017hPa 1450m
Second set of readings taken while 1100 worn on left wrist, 100 and 1300 worn on right wrist for 1.5 hours.
100-=0743h 29.9C 1019hPa 1415m
1300=0743h 29.5C 1018hPa 1440m
1100= 0744h 30.2C 1019hPa 1435m
Third set of readings were taken after the watches received 45 minutes of early morning low-angle sun sitting on a table four feet from an east-facing window.
100= 0841h 38.8C 1018hPa 1420m
1300=0842h 39.7C 1017hPa 1445m
1100=0843h 39.8C 1019hPa 1430m
Fourth set of readings taken after the watches spent 45 minutes outdoors facing the sun.
100= 0949h 52.3C 1022hPa 1380m
1300=0950h 55.5C 1022hPa 1405m
1100=0951h 54.6C 1027hPa 1360m
Fifth set of readings taken after watches rested indoors from heat test.
100= 1059h 24.4C 1020hPa 1405m
1300=1100h 24.5C 1019hPa 1430m
1100=1102h 25.2C 1019hPa 1430m
My conclusion is all three watch barometer sensors are affected by very hot temperatures [even when within the temp range specs], meaning none of these watches are compensated for heat changes.