Heat-Prober
®
Platinum-RTD Thermometers User Manual
23
8.3 Rate of Change with Hot and Cold Peak Hold (Order Option R)
This unit has microprocessor program revision E which can display any one of four different
measurements repeatedly. The four display modes are as follows:
1. Normal Temperature. The temperature as sensed by the attached probe is displayed with
updates 2.5 times per sec
ond. (Switch Position “N”).
2. Rate of Change of Temperature. The change in temperature sensed is updated every six
seconds. The rate of change is displayed in degrees per minute with proper polarity sign.
3. Hot Peak Hold. Continuous display of the hottest temperature sensed since the last time the
unit was turned on. (Switch Position “HP”).
4. Cold Peak Hold. Continuous display of the coldest temperature since the last time the unit
was turned on. (Switch Position “CP”).
If either the cold peak or the hot peak should increase, the display will be updated to read the
new colder or hotter peak. Turning the instrument off will remove the cold and hot peaks from
memory. Upon turn on, the microprocessor is reset for the input of new data.
9.0 THEORY OF OPERATION
9.1 General
The microcomputer, as directed by this program receives and evaluates data from the analog-
to-digital converter, and delivers the proper temperature values to the display driver. The
readings may be in Fahrenheit or Celsius, peak or current value.
The Flow Chart (
Figure 9.1
) shows the operation of the program. Details of the components will
be discussed in this section.
