1) Check all the clamps for tightness.
2. Check whether the water level in the tank is sufficient such that the suction pipe of pump is completely immersed.
3. For measurement through venturi, open the outlet valve of the venturi meter and close the valve of orifice meter.
4. For a good amount of variation in discharge also close the by-pass valve of pump.
5. Now switch on the pump.
6. Open the gate valve and start the flow.
7. If any air bubbles exist in U-tube manometer remove them through air cock valve. Operate the air cock valve slowly and cautiously to avoid mercury run away through water. 8. Wait for a while for stabilizations of flow.
9. Close the gate valve of measuring tank and measure the time for discharge of five liters of water and the manometer difference. Before taking any measurements, make sure the flow is stable.
10. Repeat the procedure by changing the discharge by slowly opening the by-pass valve and take the six readings.
11. Repeat the same for orifice meter.