Batteries - Alnor 9870 Owner's Manual

past 3 seconds. The way the meter averages
velocity is by saving the velocity measured each
second into separate locations in memory. Every
second, a new reading is taken and the oldest
reading is thrown out. Depending on the position of
the sensor response switch, either the last 3
readings or all 12 readings will be averaged for
display.

Batteries

The Model 9870 is powered by four AA-size
batteries. TSI ships the instrument with alkaline
batteries, but nickel-cadmium rechargeable
batteries may be used. Keep in mind that battery
life is a function of the velocity being measured: the
higher the velocity, the shorter the life. Table 2
shows typical battery life for both alkaline and
nickel-cadmium batteries at three velocities.
Table 2: Typical battery life* at three velocities
Air Velocity
(fpm)
100
1000
2000
* At 20°C
8
alkaline
(m/s)
0.5
5.0
10.0
life
(hrs)
10
6
5
nickel-
cadmium life
(hrs)
2-1/2
1-3/4
1-1/2