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Calibration
Starting Up CAL-V™
CAL-V™ may be performed at any time after installation and at any
flow rate, including zero flow. You do not need any extra equipment or
paperwork to perform a CAL-V™ test. Refer to "Performing a CAL-V™
Calibration Validation Test" on p. 74 of this User's Guide to start
CAL-V™.
Starting Up Zero CAL-CHECK™
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. 67).
•
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:
1. Packing Gland Assembly
The first in-situ option is achieved through the use of the Packing
Gland Assembly 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 beneficial for applications in
which the process is not easily stopped.
2. Pipe Bypass / Valving-Off
The second in-situ option, if space allows, is to redirect the flow
through a bypass pipe section or valve off the meter in order to isolate
the meter's sensor in the place where it has been installed. While the
flow is redirected, the Zero CAL-CHECK™ test can be performed.
Once the test is complete, the valves to the bypass may be closed
and flow may be directed back to the meter's sensor where flow
monitoring can continue as normal.
Achieving Zero Flow - Out of Pipe
If space limitations prevent in-situ testing at zero flow as listed above,
then Out of Pipe testing must be performed.
CAL-V™
Zero CAL-
CHECK™
Achieving Zero
Flow - In-Situ (In
the Pipe)
Achieving Zero
Flow - Out of Pipe