Beta 1760/IR1000 Manual Instrucciones De Uso página 36

Keep in mind thatit will take up to 30 minutes to adjust to wide ambient
temperatures are to be measured followed by high temperature
measurements, some time (several minutes) is required after the low
(and before the high) temperature measurements are made.
This is a result of the cooling process, which must take place for the IR
sensor.
11. Battery Replacement
1) As battery power is not sufficient, LCD will display " "
replacement with 2 AAA new battery type is required.
2) Open battery cover, then take out the battery from
instrument and replace with new battery and place the
battery cover back.