Model 90 Quantifier Sound Level Meter
Page 63
Changing the Battery
The Model 105 & Model 106 acoustic calibrators use a single 9v alkaline battery. This
type of battery is known as 6F22 or NEDA 1604. It is also commonly known as PP3.
1.
Unscrew the screw holding the battery cover on, using a coin.
2.
The battery, type 6F22 (PP3) can now be eased out of its holder and replaced.
The battery should be eased out terminal side first by pushing against the spring
at the other end. Ensure that the battery is inserted with the correct polarity
with the negative terminal at the contact with the larger cutout.
Battery type.
The battery should be an alkaline battery, not an ordinary dry cell. The battery is 9
volts when new and will operate the calibrator down to 6.4 volts. When the battery
voltage is below 6.6 volts but above 6.4 volts, the power LED will flash to indicate that
the battery voltage is low. When the battery voltage is below 6.4 volts the calibrator
will not turn on. A discharged battery may allow switch-on but will soon drop in voltage
and indicate low battery or switch off.
