Fluke 931 - Maintenance and Specifications; Replacing the Batteries; Specifications

5
REPLACING THE BATTERIES
Replace the batteries when LOBAT appears on display. See Figure 3.
Remove the battery cover on back of the Tachometer.1.
Replace with 2 AA 1.5V LR6 (Alkaline) batteries.2.
Replace the battery cover.3.
SPECIFICATIONS
RPM
Range
Optical (non-contact) 1 to 99999 RPM
Contact 1 to 19999 RPM
Accuracy ±0.02 % of reading + 1 digit
Sensing Distance (optical) 500 mm (20 inches)
Battery Type (2) AA 1.5 V LR6 (Alkaline)
Battery Life approximately 40 hours
Operating Temperature 0 to +50 ºC (32 to 122 ºF)
Storage Temperature -20 to +70 ºC (0 to 160 ºF)
Weight 250 g (0.55 lbs)
Size 175 x 60 x 28 mm (7 x 2.5 x 1 inch)
Note: Serial number of the Tachometer is located in battery compartment.