Description
The control of flow can only be done if the flow is also measured. Therefore a suitable flow meter hast o be choosen and connected to the dosistar.
The flow meter should be:
- Chemically resitant to the medium to be dosed
- Possess an Open-Collector-Output
- Designed for a supply voltage of 9…15V (usually: rated voltage 12V)
- Suitable for the desired flow range
IML offers suitable paddlewheel flow meters in various sizes, covering a large portion of typical dosing tasks in the agricultural sector.
Which flow meter do I need?
For optimal results in measurement and control, the correct selection of a suitable flowmeter for the desired flow range is crucial. The following table provides an initial non-binding guideline for this:
| Flowmeter Type | Flowmeter value for water Wasser [Imp/L] | max. flow [L/h] | min. recommended flow [L/h] |
|---|---|---|---|
| 1,0mm | 2223 | 35 | 9 |
| 1,2mm | 1787 | 46 | 11 |
| 1,5mm | 1386 | 80 | 13 |
| 2,0mm | 1013 | 139 | 18 |
| 2,5mm | 754 | 164 | 24 |
| 3,0mm | 572 | 293 | 32 |
| 4,0mm | 382 | 435 | 48 |
| 5,6mm | 256 | 498 | 75 |
| 7,0mm | 165 | 1080 | 110 |
If the recommended minimum flow rate is not met, there is a risk of generating too few pulses per second for a clean measurement. This can lead to measurement and control errors.
When sizing the pump, it is recommended to provide a control reserve of approximately 20%. This means that the maximum flow rate oft he pump should be 20% greater than the desired maximum flow rate of the entire system.
