4
POWER-UP THE MFM300
Press the POWER button until the display shows the Cooper logo, the remaining battery life and
the installed firmware. Press the LIGHT button to illuminate the screen in low light conditions.
POWER-DOWN THE MFM300
Press the POWER button until the display goes blank.
DISPLAY MODES
Normal mode: Displays the measured values of all the probes currently connected.
Superheat mode: Displays superheat or sub-cooling values. Requires a temperature probe be
installed in either T1 or T2 (or both) and optionally a pressure probe in U1 or U2 (or both).
Press the SH button to enter Superheat Mode. Press the SH button again, or CANCEL, to return
to Normal Mode. See the section on measuring system Superheat / Sub-cooling for further
information.
Psychrometrics mode: Displays psychrometric values. Requires a relative humidity probe to be
installed in either U1 or U2 (or both). Press the PSYCH button to enter the Psychrometric Mode.
Press the PSYCH button again, or CANCEL, to return to Normal Mode.
The MFM300 will attempt to operate in the last mode it was in when powered off. If it can not, the
Normal Mode is the default. If no probes are connected, the “No Probes” message will appear on
the display.
DISPLAY MIN, MAX AND AVG VALUES
When in Normal Mode press:
MIN
button to display the lowest readings sensed by each probe.
MAX button to display the highest readings sensed by each probe.
AVG button to display the average readings sensed by each probe.
The active mode, MIN, MAX or AVG, will be indicated near the bottom of the display. Pressing
the same button again, or CANCEL, turns off the selected mode. Disconnecting a probe will
clear that probe’s MIN, MAX, and AVG memory, but all probes still connected will continue to
be updated. All MIN, MAX and AVG memory is lost when the MFM300 is powered down.
MEASURE TEMPERATURE
Install one, two, or three Cooper 10K thermistor probes into any of the three temperature jacks:
T1, T2 or T3. The MFM300 will sense the probe and display the temperature measurement with
the appropriate label.
MEASURE TEMPERATURE DIFFERENCE (DELTA T)
With two probes connected, press the DELTA button until “Delta T” appears on the display. The
absolute temperature difference appears to the right of the horizontal bars that point to the two
temperature inputs being measured. Press the DELTA button again, or CANCEL, to turn off the
“Delta T” display. If three temperature probes are connected, press the DELTA button again to
display the next “Delta T”. With three temperature probes connected, the “Delta T” sequence is
as follows:
