Omega Engineering FLR1000 manual

If the unit has a flow reading of 200ml/min then the corrected flow reading (for CO2) would be:

Corrected Flow = 200 X 0.88 = 176 ml/min

CAUTION:. The use of correction factors can be subject to inaccuracy and errors of up to ±10%. Please contact the Omega Engineering Service Department if accurate, certified recalibration is required.

Calculating a correction factor for a gas enables the calibration of the unit to be adjusted for that gas. This is accomplished by:

i)Calculate the corrected flow reading or VDC output at 100% of flow using the above formulas.

ii)Adjust the flow of (the new) gas to give this flow reading

iii)Maintain this flow and ensure a stable reading.

iv)Adjust the gain potentiometer on the unit so that a 5VDC output is obtained. The unit is now calibrated for the new gas.

For example: A 2.0 -10.0 l/min unit that has been calibrated for Air is to be used with CO2. The correction factor, calculated as above, is 0.88. When flowing CO2 the unit will read high i.e. at 5VDC the flow of CO2 would actually be 8.8 l/min and not 10 L/min. A flow of 10 l/min of CO2 through the unit would give a reading of 10/0.88 = 11.36 l/min or 5.68 VDC on the unit. Flow should be adjusted so that an output of 5.68VDC or reading of 11.36l/min is obtained. The gain potentiometer is then adjusted so that the voltage output becomes 5VDC or the display reads 10l/min. The unit has now been adjusted for CO2 and no further corrections to flow readings are required (if flowing CO2).

It should be noted that the maximum output voltage for the units is approximately 5.9VDC. It is not possible to adjust units if an output of greater than 5.9 VDC is required.

Adjusting the Gain Potentiometer Using a Flat Head Screwdriver

(FLR 1000 shown, other models similar)

pg. 15 of 29