Emerson Micro-Motion 2400S, Configuration And Use Manual, Page: 112 / 198

104 Micro Motion
®
Model 2400S Transmitters with Analog Outputs
Measurement Performance
Note: For density or temperature calibration to be useful, the external measurements must be
accurate.
Micro Motion flowmeters with the Model 2400S transmitter are calibrated at the factory, and
normally do not need to be calibrated in the field. Calibrate the flowmeter only if you must do so to
meet regulatory requirements. Contact Micro Motion before calibrating your flowmeter.
Micro Motion recommends using meter validation and meter factors, rather than calibration, to prove
the meter against a regulatory standard or to correct measurement error.
10.2.4 Comparison and recommendations
When choosing among meter verification, meter validation, and calibration, consider the following
factors:
• Process and measurement interruption
- Smart Meter Verification provides an option that allows process measurement to continue
during the test.
- The original version of meter verification requires approximately three minutes to
perform. During these three minutes, flow can continue (provided sufficient stability is
maintained); however, measurement is halted.
- Meter validation for density does not interrupt the process or process measurement.
However, meter validation for mass flow or volume flow requires process down-time for
the length of the test.
- Calibration requires process down-time. In addition, density and temperature calibration
require replacing the process fluid with low-density and high density fluids, or
low-temperature and high-temperature fluids.
• External measurement requirements
- Neither version of meter verification requires external measurements.
- Zero calibration does not require external measurements.
- Density calibration, temperature calibration, and meter validation require external
measurements. For good results, the external measurement must be highly accurate.
• Measurement adjustment
- Meter verification is an indicator of sensor condition, but does not change flowmeter
internal measurement in any way.
- Meter validation does not change flowmeter internal measurement in any way. If you
decide to adjust a meter factor as a result of a meter validation procedure, only the reported
measurement is changed – the base measurement is not changed. You can always reverse
the change by returning the meter factor to its previous value.
- Calibration changes the transmitter’s interpretation of process data, and accordingly
changes the base measurement. If you perform a zero calibration, you can return to the
previous zero or the factory zero. However, if you perform a density calibration or a
temperature calibration, you cannot return to the previous calibration factors unless you
have manually recorded them.
Micro Motion recommends that you perform meter verification frequently. If verification fails and
there is no problem with the sensor or the process, perform meter validation and adjust the meter
factors. If this is not sufficient, you may want to perform a field calibration.