Support / Technical Tips / How to measure your output
How to measure your output
A quick, reliable way to test your system's real flow rate at sea.
You'll need
A 500ml measuring cup, and your phone.
Steps
- Start your system and leave the Sample/Tank valve on Sample.
- Put your phone into stopwatch mode.
- Time how long it takes to make 500ml of water.
- Switch your phone to calculator mode and divide 1800 by the number of seconds. The answer is your output in litres per hour.
Why 1800? We measure half a litre because it's easy and accurate. The number of half-litres you make in half an hour is the same as the number of litres you make in an hour, and there are 1800 seconds in half an hour.
Expected times
Common production rates for our systems, and how long each takes to make half a litre:
| Output | Seconds per 500ml |
|---|---|
| 35 L/h | 52 |
| 70 L/h | 26 |
| 80 L/h | 22.5 |
| 160 L/h | 11.25 |
| 240 L/h | 7.5 |
Reading the result
Water temperature affects production. Warmer seawater makes fresh water more quickly. The nominal seawater temperature is 25 degrees.
If your system is making water faster than it should, the most likely cause is low salt content in the source water. This is common near river outflows and in inlets.
For the long-term health of your membranes, keep production no more than 15% above nominal. Each 2.5 x 40 inch membrane has a nominal output of 80 litres per hour, so lower the system pressure until each membrane makes no more than 92 litres per hour.