A meter can be calibrated with the medium that is used in the process, then the calibration reaches the highest level of accuracy, for example with air, water or natural gas.
If the above is not the case Errakal's wide range of flow facilities can be used for the calibration of your steam measurements and of other media for which no straightforward calibration facility is available. If the medium of calibration is not the same as the medium of the process, the method of Reynolds can be used. Two different currents with identical Reynolds number (Re number) are technically identical. The calibration of the meter is carried out in the same Re area as of the Re area of the application. In this way the meter is adapted to the application to get the lowest possible uncertainty.
The liquid rig for instance can carry out calibrations with liquid temperatures up to 80 degrees Celsius and viscosities up to 70 cSt (small diameter up to 200 cSt). The Re area of this rig is max 2,200,000 (DN150) or 750,000 (DN50).
In the air rig calibrations under pressure up to 6 bara can be performed. The Re area of this rig is shown in this graph. (click here)
To check your meters Errakal has a service that can save costs. This service is called fingerprinting. The initial calibration of the meter is required on some external rig, e.g. 40 bar natural gas. After this calibration the meter is calibrated at Errakal with water or air. At the next check of the meter, only the water or air calibration at Errakal is repeated. If the measured values are within a pre-agreed bandwidth, then the initial calibration is still valid. The advantages of this method are that the cost of recalibration is lower, the plant availability is greater and the turnaround time is significantly shortened.
Errakal can also administer the calibration of meters for sizes or flow rates which are not available at our own facilities. Also calibrations with natural gas or steam are possible under administration of Errakal. Errakal controls transportation, witnesses the "external" calibration and writes the reports. (Also think about a total package including calibration of pressure- and temperature devices and the above mentioned fingerprinting). Errakal can take care of the revision and/or repair of flow meters with an independent third party. (possible recalibration included)
The above mentioned flow calibration rigs are also suitable and used as research facility for test programs on flow meters. These research programs can be executed by Errakal experts or by the customer themself.