Fluke 9107 - Manual (Page 33)

8.5.1 Hold Temperature Display
When the hold feature is enabled you can easily switch the display between the
normal temperature display and the hold temperature display by simply press-
ing the “UP” or “DOWN” buttons. The hold temperature display shows the
hold temperature on the right and the switch status on the left. For the status
“c” means the switch is closed and “o” means the switch is open. The status
flashes when the switch is in its active position (opposite the normal position).
The hold temperature shows what the temperature of the well was when the
switch changed from its normal position to its active position. While the switch
is in the normal position the hold temperature will follow the well temperature.
Operation of the hold temperature display is outlined below.
43.56 C
Well temperature display
U
Access hold display
c 44.8C
Switch status and hold temperature
Note that the hold function display is not accessible if the function mode is set
to “OFF”. (See Section 8.5.2)
To return to the normal well temperature display press “DOWN” or “EXIT”.
8.5.2 Mode Setting
The temperature hold feature has three modes of operation. In the nor-
mally-closed (n.c.) mode the hold temperature display freezes when the switch
opens. In the normally-open (n.o.) mode the hold temperature display freezes
when the switch closes. Whenever the switch is in the normal position the hold
temperature follows the well temperature.
There is also an automatic mode. In this mode the normal position is set to
whatever the switch position is when the set-point is changed. For example, if
the switch is currently open when the set-point is changed, the closed position
then becomes the new active position. The normal position will be set automati-
cally under any of the following conditions, (1) a new set-point number is se-
lected, (2) the set-point value is changed, (3) a new set-point is set through the
communications channels, or (4) the ramp-and-soak program is running and
automatically steps to the next set-point in the sequence. The automatic mode is
useful for repetitive tests of the opening and closing temperatures of a switch.
The temperature hold feature can also be disabled by setting the mode to
“OFF”.
The operating mode of the temperature hold is set in the primary menu after the
scan rate setting.
28 Hart Scientific
8 Controller Operation