Temperature Probe - Teledyne 4250 Installation And Operation Manual

4250 Flow Meter
Section 4 Options and Accessories

4.9 Temperature Probe

4-14
• The probe cable is carefully routed out of the stream.
• Only the temperature probe can connect directly to the
flow meter's parameter probe connector.
• The pH and D.O. probes both connect to parameter
modules (amplifiers). The pH probe connects to the 201
pH Module and the D.O. probe connects to the 270 D.O.
Module. The modules are not interchangeable.
Note
The 270 D.O. module has been discontinued. Probes, service
kits, and accessories are still available to maintain existing field
units.
Isco flow meters are built with one parameter sensing port, and
can only sense temperature plus one parameter at a time, (unless
you use the YSI Sonde.) You must select temperature, D.O. with
temperature, or pH with temperature. If you want to change
probes later, you can, but you will need to reprogram the flow
meter. Note that selection of either pH or D.O. in step 1 (where
units of measure are defined) will lock out any mention of the
other in the menus for the rest of the program.
The Parameter Modules themselves plug into the Parameter
Probe connector on the flow meter.
The pH and D.O. probes require continuous submersion after
installation, or they will lose sensitivity. Prolonged dehydra-
tion of the sensor bulb may damage or even ruin the pH
probe.
The temperature probe is the simplest of the three, consisting of
a thermistor inside a metal housing. The thermistor changes
resistance with an increase or decrease in temperature. The flow
meter converts this resistance change to a temperature reading
and displays it, in degrees Celsius or Fahrenheit, as chosen by
menu selection.
CAUTION