Mr Ling has no need to use water and a stopwatch to test the flow rate of any suction machine!
In Lincoln we use a gas flow meter set to measure air flow to check the suction flow. The old style Laerdal suction unit is expected to be able to produce 10 litres / min on half setting and 20 litres / min on full setting. The new style one is expected to produce > 25 litres / min at maximum setting.
