Mastech MS2016A Operation Manual page 4

1.2.15 Measure known voltage with the meter to verify
that the meter is working properly. If the meter is
working abnormally, stop using it immediately. A
protective device may be damaged. If there is
any doubt, please have the meter inspected by a
qualified technician.
1.4.1 Don't try to open the meter bottom case to adjust
or repair. Such operations can only be performed
by technicians who fully understand the meter and
electrical shock hazard.
1.4.2 Before opening the meter bottom case or battery
cover, remove probe from the circuit to be measured.
1.4.3 To avoid wrong readings causing electric shock,
when " " appears on the meter display, replace
the battery immediately.
1.4.4 Clean the meter with damp cloth and mild detergent.
Do not use abrasives or solvents.
1.4.5 Power off the meter when the meter is not used.
Switch the measuring range to "OFF" position.
1.4.6 If the meter is not used for long time, remove the
battery to prevent the meter being damaged.