Fox Thermal FT3 - Page 78

takes less than 5 minutes to complete. At the conclusion of the test, a Pass or Fail message will be
displayed. Press F4 at the conclusion of the test to return to normal measuring mode or to terminate
the test.
There are a few ways that Zero CAL-CHECK
™
is different than CAL-V™:
• The Zero CAL-CHECK
™
test must be performed at a "no flow" condition (ie zero flow)
• If the Zero CAL-CHECK
™
test is to be performed in the pipe, the field baseline must be set before
an actual test can be performed (see "Setting Field Baseline for In Situ Zero CAL-CHECK
™
Tests" on
p. 79).
• If the Zero CAL-CHECK
™
test is to be performed out of the pipe, the meter must be set upside-
down (probe pointing up) and the PVC sensor protector that the meter was shipped with must be
placed back over the sensor to achieve the factory baseline that the meter has been set with.
Techniques for Achieving Zero Flow - In the Pipe
In situ (in the pipe) Zero CAL-CHECK
™
testing can be achieved in one of two common ways:
• Fox Thermal Retractor
• The rst in situ option is achieved through the use of a Fox Thermal retractor that may be
ordered as an option for most inline- or insertion- type meters. The assembly allows the
operator to retract and isolate the sensor from the process in order to conduct the Zero CAL-
CHECK
™
test. This is particularly benecial for applications in which the process is not easily
stopped.
• Pipe Bypass / Valving-O
• The second in situ option, if space allows, is to redirect the ow through a bypass pipe section
or valve o the meter in order to isolate the meter's sensor in the place where it has been
installed. While the ow is redirected, the Zero CAL-CHECK
™
test can be performed. Once the
test is complete, the valves to the bypass may be closed and ow may be directed back to the
meter's sensor where ow monitoring can continue as normal.
Achieving Zero Flow - Out-of-Pipe
If space limitations prevent in situ testing at zero ow as listed above, then out-of-pipe testing must
be performed.
With this conguration, the meter must be removed from the process, the test performed, and then
the meter returned to the process after testing has been completed.
Due to the high sensitivity of the PowerPro™ sensor, it is necessary to isolate the sensor once the
meter has been removed from the pipe. Therefore, Fox Thermal provides a sensor cover when the
meter is shipped to the customer. An alternative to the sensor cover is to use a bottle or other closed
container in order to isolate the sensor and achieve the "no ow" condition necessary to perform the
Zero CAL-CHECK
™
test.
Operation | 78
Model FT3
Operation