MTP AT-8 Manuel D'instructions page 3

Data Storage: Press the "MEAS" button until the reading is displayed. Observe the
reading and press the "MEM" button to save data. The maximum, minimum and
average values together with data of a single-shot measurement will be stored into a
memory set and the data number will then increase by one.
Recall Data: Use the "MEM" button to scroll and view the stored data point. Press the
"MEM" button once for next storage; you can view the MAX, MIN, AVG and DATA
values. Press and hold the "MEM" button to go to the next data set. You can view
Data0 to Data9 (10 selectable data measurements).
Measurement Mode Switch : Release the "MEAS" button and press the "MODE" button
before the instrument auto powers itself off (if you release the "MEAS" button, the instrument
will automatically power off after 15 seconds). There are two modes of measurements. You can
press the "MODE" button once to switch between RPM, rpm, Hz, etc. Press the "MODE"
button and hold it for approximately 3 seconds to go to the next mode of measurement. Then,
press the "MODE" button once to switch between REV, M, In, etc. Select the desired
measurement mode and press on the "MEAS" button to start measurement.