e. Tachometer. The tachometer indicates the angular velocity of the centrifuge
rotor in thousands of rpm. The meter scale is graduated from "0" to 4,000 rpm in
increments of 100 rpm. When the centrifuge cycle is started, the tachometer needle may
not immediately move off the "0" point on the meter scale until the rotor speed reaches
approximately 500 rpm.
The tachometer is accurate to within+5 percent over the range of 500 rpm to
Never operate the centrifuge without a rotor installed. You could damage
f. Cover Safety Latch Assembly. The centrifuge cover is held closed by a
lever-type lid latch which is spring-actuated to release when pressed. In addition, the latch
assembly on the centrifuge bowl incorporates the following safety features:
(1) Safety switch. When the cover is closed and latched, an electrical
interlock is engaged, and power is supplied to the motor. You cannot start the centrifuge
while the cover is open.
(2) Zero speed switch. Once the centrifuge is running, a zero speed switch
prevents the cover from being opened (unlatched). You cannot open the cover until the
rotor slows to less than 1 revolution per second (50rpm).
To lock the cover, press down on the latch and cover until you hear
an audible click.
(b) To open the cover, wait until the rotor has stopped spinning and then
press the latch as shown in figure 1-3.
Figure 1-3. Cover latch.