There are many options to calibrate a Laminar molbloc to make it flexible for use in a variety of applications and maintain its published specifications.
It is often best to look at your prior cal reports to verify what was done previously and do the same if not needing to change how they are used.
There are three choices to make:
- Which gases to get the molbloc calibrated for?
A gas calibration is required for the gas that is actually flowing through the system. Even if you are flowing say Air and have a calibration for N2 this can produce significant measurement error. Gases can be added or removed as necessary. - What calibration type is needed? Here are the options:
Low Pressure (LoP Upstream) - This is the default calibration type if this was not changed during the sales process or later. Operating pressure needs to be 200 to 325 kPaa (29 to 47 psi) at the upstream transducer of the molbloc. Typically the device being tested would be run downstream of the molbloc with this calibration type but that is not always the case as it would not matter as long as the pressure on upstream transducer is held properly one way or another.
High Pressure (HiP Upstream) - This calibration is typically chosen when higher flow rates are desired as the higher pressure typically allows you to flow twice as much as the Low Pressure calibration. Operating pressure needs to be 325 to 525 kPaa (47 to 76 psia). at the upstream transducer of the molbloc. Typically the device being tested would be run downstream of the molbloc with this calibration type but that is not always the case as it would not matter as long as the pressure on upstream transducer is held properly one way or another. Note that a high pressure calibration is not available on a 1E5-L molbloc element.
Downstream (Down) - This calibration is typically chosen when it is known the molbloc will be run downstream of the device being tested and the molbloc outlet will be open directly to atmospheric pressure. The downstream pressure thus needs to be in atmospheric pressure range of 85 to 110 kPaa (12 to 15 psia). - What uncertainty/accuracy class is needed?
Standard - Provides a nominal 0.2% of reading down to 10% of full-scale when used with molbox1+ or molbox1 flow terminal. For molbox RFM terminal it is nominal 0.5% reading down to 10% of full-scale.
Premium - Provides a nominal 0.125% reading down to 10% of full-scale. This calibration is only available for use when using a molbox1+. Note that Premium class calibrations are not available on 1E1-L and 1E5-L molbloc elements.
*** multiple gases are supported on molbox1+, molbox1, and molbox RFM. For example you could have N2, Air, and SF6 gases on a single molbloc.
*** multiple calibration types are supported on molbox1+ and molbox1 but NOT on molbox RFM. For example you could have N2 Low Pressure, N2 High Pressure, and SF6 Downstream on a single molbloc if using a molbox1+ or molbox1.
*** The above info is assuming the molbox is an A700K model. If you have the less common A350K model you are restricted to Low Pressure and Downstream calibrations.
*** Uncertainty/accuracy statements are for nominal value. The % reading will not be valid below a certain % of full-scale threshold. See molbox/molbloc flow calibration system uncertainty analysis for full details.
See the article below for further info on how to use a molbloc element with different calibrations or the User Manual:
Quick-start guides for using molbox/molbloc-L flow calibration system