A possible cause of a calibration or flow alarm is an empty calibration gas cylinder. After replacing the calibration gas cylinder or an abnormal outgoing pressure the flow should be checked and adjusted.

To replace a calibration gas cylinder, follow these steps:
1. Check that the bottle is actually empty.
2. Open valve 1 fully and check the pressure in the bottle on
pressure gauge 2.
3. Close valve 1 again as soon as it reads 0 bar.
4. Use a suitable wrench to unscrew connection 5 and remove the reducing valve.
5. Insert a full calibration gas bottle and tighten connection 5 firmly.

To adjust a calibration gas cylinder, follow these steps:
1. Pressure gauge 3 shows the output pressure of the bottle.
2. Since only an air flow of 1 liter per minute is required during calibration, pressure gauge 3 will
read close to 0 bar.
3. While calibrating the measurement system with calibration gas (calibration gas 1), you can
read the flow on the flow meter on the measurement box.
4. During calibration of calibration gas 1, the output pressure (flow) is adjusted using
adjustment valve 4.