Teledyne 4220, Installation And Operation Manual, Page: 123 / 198

4220 Flow Meter
Section 5 Options and Accessories
5-15
Greasy substances, being nonconductors of electricity, weaken
the electrical potentials formed between the glass mono-electrode
and the solution, slowing or halting the response altogether.
The pH Sensor operates satisfactorily mounted either horizon-
tally or vertically in the stream. However, horizontal mounting is
more secure, and presents less of a debris trap.
• Simple suspension of the probe is not recommended,
particularly in streams of high velocity, or those that
carry debris.
If you mount the pH probe vertically, mount it securely. Do not
just hang it from the top of the pipe by its cable. Suspending the
probe in the stream is not stable.
For horizontal mounting, the probe fastens to a sensor carrier
that snap-fits to an Isco mounting ring. The mounting rings fit
various diameters of round pipes 15" diameter and smaller. For
larger pipes, use the
Isco Universal Mounting Ring . For
installation details, refer to the instruction sheet supplied with
the mounting ring.
The mounting rings are held in place by the outward force of
spring pressure in the smaller sizes and by a screw arrangement
in the larger sizes. After mounting the probe in the ring or strap,
route the cable out of the stream so it will not trap debris that
could clog the sewer.
Mount the pH Module within 25 feet of the probe, but in a
location higher than the highest anticipated level for the flow
stream. The amplifier box is sealed and will withstand tem-
porary submersion, but this should be avoided.
Note
Do not connect an Isco pH probe and temperature probe to the
201 module at the same time. The “Temperature Probe” input
on the 201 module is for use ONLY with non-Isco pH probes
that do not have built-in temperature sensing. The Isco pH
probe contains its own integral temperature sensor, which, if
connected in parallel with a separate temperature probe, will
cause erroneous readings.