HFM-401/405 - Teledyne Hastings Instruments

2.2. Rotary Gas SelectorThe Hastings 400 Series flow meters can have up to eight different calibrationsstored internally. These are referred to as gas records. These records are usedto select different gases, but they can also be useful in other ways; for instancereporting the flow in an alternate range, flow unit or reference temperature.The records are referred to by their number label from #0 – #7.The first six records will, by default, be setup for most common six gases asshown in Figure 2-11. If a gas other than one of these six is specified on thecustomer order it will be placed in record #6. If a second different gas isselected, it will be placed in record #7. If multiple different gases or ranges arespecified they will replace some of the standard six gases.The purchased calibration certificate is provided for the gas (orgases) specified by the customer when ordering. This gas will beindicated with an “X” on the Gas Label (diagram below) that islocated on the top of the 400 Series Mass flow meter’s electronicsenclosure. The remaining gas records will have a different full scalevalue and an unverified calibration. The full scale rangecan be calculated by using the Gas conversion factor orGCF. A comprehensive list is found in Appendix 2 inthis manual.X0 N21 Air2 He3 H24 Ar5 O267S/NX= cal reportgenerated(others use GCF)Record#Record# Gas0 Nitrogen1 Air2 Helium3 Hydrogen4 Argon5 Oxygen6 Custom7 CustomFigure 2-11 Gas record tableFull ScaleRangeGas0 Nitrogen 100 slm1 Air 100.15 slm2 Helium 140 slm3 Hydrogen 100.38 slm4 Argon 140.37 slm5 Oxygen 97.95 slm6 Custom7 CustomNot included ifnot specifiedNot included ifnot specifiedExample 1To convert the calibration of a full scale range of 100 slm of Nitrogen to the other full scale ranges:FS = FS21GCFGCF211. Calculate full scale value of HeliumCalibrated gas = Nitrogen (GCF1 = 1.000)Full scale range (FS1) = 100 slmSecondary gas (FS2) = Helium (GCF2 = 1.40)1.40/1 = 1.40, 1.40 x 100 = 140 slm of Helium2. Calculate full scale value of HydrogenCalibrated gas = Nitrogen (GCF1 = 1.000)Full scale range (FS1) = 100 slmSecondary gas (FS2) = Hydrogen (GCF2 = 1.0038)1.0038/1 = 1.0038, 1.0038 x 100 = 100.38 slm of Hydrogen401-405 SERIES - 12 -