The 3401 scaler is shown in Figure 3.
The PWR/TIME switch is used to select SLOW, NORMAL, and
FAST count times (4 minutes, 1 minute, and 15 seconds). The
display switch chooses MOISTURE or DENSITY, and the
〈START〉 key begins count accumulation.
Moving the MEAS/TST switch to TST toggles the test routine
(see Chapter 6).
Figure 3. 3401-B Front Panel Controls