Professional Calibration Services Keep Your System Flowing

Professional Calibration Services | Flowmetrics

Flow is a crucial measurement in any system, large or small. It helps indicate the status and efficiency of the upstream equipment and what to expect for downstream equipment. It also helps operators determine the process output, balance mass throughout the system and determine characteristics about the transported fluid. Continue reading “Professional Calibration Services Keep Your System Flowing”

The Art of Calibrating

The Art of Calibrating | Flowmetrics

Basic calibrations of sensors combine a known environment tied to an output of that sensor. If a pressure sensor outputs a value of 2 psi when in a vacuum and 102 psi when placed inside a space with known pressure of 100 psi, the operator can calibrate the sensor to output 2 psi less than it currently does. Usually a sensors output is a linear affair between the stimuli and the reading it provides, and in these cases calibration is simple. By calibrating in this way the operator is introducing errors if they are off in any way.

If the testing situations are not accurately known any readings after calibration will have the same discrepancies. The use of a “golden unit” or a standardized unit of measurement to calibrate all sensors against can vastly reduce this type of error.

The calibration procedure should produce consistent results. If the operator can use the same procedure and calibrate the same sensor multiple times to the same end value then a sensor is much more likely to be accurate. If the sensor has varying levels of offset at the end each time, something must be fluctuating between calibrations.

 

Click here for the full article by Jim McCarty.

Coriolis Flow Meter Calibration

Coriolis Flow Meter Calibration | Flowmetrics iStock_000058054942_Medium

Calibrating a flow meter means first testing the meter for its unique deviation from reality, then altering the meter or program in some way to negate that unique offset. Each meter has its own flaws, quirks, and strengths well within the standards to adjust for in specific applications, and calibration tests are designed to identify these for adjustment later.

At first a two-by-two hypothesis matrix is used to determine if the meter reads a true positive, false alarm, covert failure, or true negative based on an assumption of how the meter will read. If it is assumed the meter is accurate and tests to read accurately the result is a true positive. A meter suspected to be inaccurate that reads inaccurately is a true negative. Other variations produce covert failures or false alarms. Balance between false alarms and covert failures is the key in flow meter calibration.

The perfect flow meter — zero calibrations, zero proving, no zeroing and zero worries with powerful diagnostics that can verify meter accuracy and give advance warning of changes — does not yet exist. Coriolis may arguably be the closest technology
because it is largely insensitive to fluid properties. It is predicted that within 10 years, on-board meter verification diagnostics will be a standard expectation in Coriolis technology.

 

Click here for the full article by Tom O’Banion.