In the science of measurement, a standard is an object, system, or experiment that bears a defined relationship to a unit of measurement of a physical quantity.  These standards are the fundamental reference against which they compare all other devices.

In pressure calibration, there are many terms that are interchangeably used.  One of them is the primary reference pressure standard.

What is the Primary Reference Standard?

It is the primary instrument you are using as a reference to measure pressure in a standard way.  The instruments that are referred to is deadweight testers, pressure balances, and piston gauges.  These are all traceable to SI units.  Using any of these devices is essential to a fully equipped pressure calibration lab.

Instruments Used for Pressure Reference

These instruments provide a pressure reference to compare the reading of a device under test during a calibration.  They may use a pressure transducer in the field.  In order to accurately measure a process pressure or to test and calibrate instruments on a production line.  To ensure consistent and accurate measurement, these instruments require a more accurate calibration involving a primary reference standard.

It is important for a reference standard to be as accurate as possible in order to ensure these field pressure devices meet their accuracy requirement for a specified interval.

Traceability through Primary Standards

The measurements of indicators, handhelds, and other instruments used to calibrate pressure sensors in the field should be traced back to SI units.  It achieves this unbroken chain of traceability through the measurements of primary reference standards.  These standards’ measurements are directly traceable to SI through their country’s National Metrology Institute (NMI).

It achieves traceability to SI because these instruments use the primary units, kilogram (kg), meter (m), and second (s) to realize their measurements of pressure.  Along this chain of traceability, more and more accurate devices can calibrate each successive device.  Therefore, all are ultimately traceable to SI.

Repeatability with a Reference Standard

Another key aspect of calibration is repeatability.  Since, these primary reference pressure standards use mass in a gravitational field and a dimensionally stable piston and cylinder system to measure and produce pressure.  It’s essential in their operation that they are consistent and repeatable when all environmental conditions are accountable.  Primary standards provide uniformity to calibration that specifically guarantees repeatability and contributes to the desired level of quality and accuracy to meet each requirement.

From piston gauge to primary reference pressure standard, what is important in pressure calibration is providing consistent and reliable readings that meet your accuracy requirements.

SRP Control Systems Can Help

If you are still unsure about the standards that you need for your lab, we can help.  SRP control systems can help you take care of your equipment with one of the largest pressure laboratories in Canada.  We are an ISO 17025 accredited laboratory and can calibrate your equipment to meet your needs.  There will be no surprises, and your instruments and equipment will be accurate and compliant.