Acumen Stopwatch Instruction Manual page 26

Tips:
1) Press & hold EL Button
will change the Temperature Display in Fahrenheit or Celsius.
2) When you switch to the Heat Index Display (referred to page 81 to get to
know the Heat Index) and HI value currently at a very high level, the watch
will alert you by toggling between the Heat Index value and warning
indication as followed:
Range: 80 - 89
Range: 90 - 104
22
for 3 seconds when in the Temperature display
A
Auto
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Auto
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