A calibration gas is a reference gas mixture used as a comparative standard in the calibration of analytical instruments, such as gas analysers, gas chromatographs or other gas measurement devices. If it is important that the instrument is capable of making good measurements, then the reference standard used to calibrate it is equally important.
Throughout this paper we are going to look at what makes a good calibration gas, the benefits it can provide and how it all relates to the measurement of Natural Gas or LNG. ...read more.
Fiscal Measurement must not be confused with Custody Transfer; in fact, fiscal measurement is a more general term meaning “measurement for money” that includes both allocation and custody transfer flow measurement.
Combined cycle gas turbine (CCGT) power stations, combined heat and power (CHP) plants, gas storage sites and intensive energy using industries burn or handle very large quantities of gas per annum. This gas usually represents one of the greatest input costs (and hence risks) to their business, a cost which is mainly determined by the accuracy of their gas metering and the price paid for the gas. Companies often go to great lengths to make sure the commercial arrangements for gas purchase are as favourable as possible, but overlook the obvious question: Actually, how accurate is our gas metering? Read more...
Written by Bob Thomson, Principal Flow Measurement Consultant, EffecTech Ltd.
A calibration gas is a mixture of gaseous components used as a comparative reference in the calibration of analytical instruments, such as gas analysers or gas detectors. Calibration is important for all testing instruments and the calibration gas is a means of establishing a known response to a certified chemical component concentration. This paper looks at the key aspects to be aware of when procuring and using calibration gas. We will examine common terminology including metrological hierarchy, traceability, accreditation and units.
Natural Gas is made up of several component gases and is therefore subject to natural variation. This inconsistency affects the energy contained within a given volume of gas. Gas quality is most commonly described based on the measurements taken of the heating value, also known as calorific value, Wobbe Index, relative density, among others.
One of the most frequently asked questions EffecTech receives is what is the ISO 10723 performance evaluation and why is it necessary? This short technical paper has been prepared to answer these questions and allow potential customers to make an informed decision.
Natural gas and LNG are traded on total energy delivered. Energy delivered is the product of volume flow and gas quality. It follows that errors and uncertainties in the measurement of gas quality or flow will affect the total energy calculation. Due to the large volumes of natural gas flowing across fiscal custody transfer points even a very small error in either measurement can lead to large financial discrepancies.
This paper will look specifically at ways to help reduce errors and uncertainties in gas quality measurements. Read more...