Rosemount 8712, Reference Manual

Page: 145 / 212

Reference Manual
00809-0100-4664, Rev BA
January 2010
C-13
Rosemount 8712
Optimizing the 8714i
Meter Verification
The 8714i Meter Verification diagnostic can be optimized by setting the test
criteria to the desired levels necessary to meet the compliance requirements
of the application. The following examples below will provide some guidance
on how to set these levels.
Example
An effluent meter must be certified every year to comply with Environmental
Protection Agency and Pollution Control Agency standards. These
governmental agencies require that the meter be certified to five percent
accuracy.
Since this is an effluent meter, shutting down the process may not be viable.
In this instance the 8714i Meter Verification test will be performed under
flowing conditions. Set the test criteria for Flowing, Full to five percent to meet
the requirements of the governmental agencies.
Example
A pharmaceutical company requires bi-annual verification of meter calibration
on a critical feed line for one of their products. This is an internal standard, but
plant requirements require a calibration record be kept on-hand. Meter
calibration on this process must meet one percent. The process is a batch
process so it is possible to perform the calibration verification with the line full
and with no flow.
Since the 8714i Meter Verification test can be run under no flow conditions,
set the test criteria for No Flow to one percent to comply with the necessary
plant standards.
Example
A food and beverage company requires an annual calibration of a meter on a
product line. The plant standard calls for the accuracy to be three percent or
better. They manufacture this product in batches, and the measurement
cannot be interrupted when a batch is in process. When the batch is
complete, the line goes empty.
Since there is no means of performing the 8714i Meter Verification test while
there is product in the line, the test must be performed under empty pipe
conditions. The test criteria for Empty Pipe should be set to three percent, and
it should be noted that the electrode circuit health cannot be verified.