Ive played around with an 25mm one,had too much restriction on my mains on the impellor part that when you looked in he bore was oly half the area.
THat one linked is only ~12mm so I would expect even more restriction.
Fluc |
The flow meter spec says:
This listing includes 1 unit of electronics flow meter. (size:G1/2"), male and female connection.
Function: For the sense of the water flow rate on the following equipments: Thermostatic water heater, water purifier, water dispenser, smart card equipment, coffee machine etc.
Calculation Formula: F(Hz)= 8.1*flow rate(Q)-6(l/min)
Note:
1. When magnetic material is close with the sensor, its characteristics may vary.
2. In order to avoid particle debris, the sensor must be installed after a filter.
3. The flow sensor installation has to avoid strong vibration and shaking of the environment, so as not to affect the sensor's measurement accuracy.
Features:
4. Copper material, environmental friendly material, small, flexible and functional.
5. Intubation design of inlet and outlet pipe, easy connection and operation;
6. Imported Hall IC from Japan, stable and reliable;
7. Range: 1-30L/min;
8. working voltage: DC3-18V;
9. rated voltage: DC5V;
I don't think that sensor can generate pulses, it's a hall element, so the output tension varies with the water-flow. Or you have to use the schematic i used for temperature readings (voltage to frequency IC = LM331) See also below in the measuring temperature topic.
10. Output voltage(rated: DC 5V); High level 4.5V and above; low level 0.5V and below
11. Pulse output duty cycle: 50+-10%
12. Insulation resistance: 100M Ohm and above;
13. Tightness: Seal up all the holes, and inflate with 1.7MPa water, after 1 minute, no leakage and deformation;
14. -20-80 Cel.degree;
Fluc |
Ohh, i messed with the comment in the specs between 9 and 10... cant change that anymore !
gebhardm |
As the formula indicates it must be pulses; I bet, the hall element is not used proportionally to measure a magnetic field's strength, but works as a magnetic switch as replacement for a reed switch; there are hall sensors with built in Schmitt-trigger that deliver a "high" on magnetic field present and "low" if not...
To get the meter constant you now have to calculate what one impulse actually means - from the formula there is 2.1Hz at 1l/min and 237Hz at 30l/min...
If it is an impeller then one turn would equal one impulse and would have transported what volume through the cross-section of the flow channel?
Fluc |
Ok, Markus, it's correct that there are pulses, i didn't read it well, big mistake of me.
In the specs on point 10 and 11:
10. Output voltage(rated: DC 5V); High level 4.5V and above; low level 0.5V and below
11. Pulse output duty cycle: 50+-10%
I just wondering if the pulses are proportional and linear to the flow.
Ive played around with an 25mm one,had too much restriction on my mains on the impellor part that when you looked in he bore was oly half the area.
THat one linked is only ~12mm so I would expect even more restriction.
The flow meter spec says:
This listing includes 1 unit of electronics flow meter. (size:G1/2"), male and female connection.
Function: For the sense of the water flow rate on the following equipments: Thermostatic water heater, water purifier, water dispenser, smart card equipment, coffee machine etc.
Calculation Formula: F(Hz)= 8.1*flow rate(Q)-6(l/min)
Note:
1. When magnetic material is close with the sensor, its characteristics may vary.
2. In order to avoid particle debris, the sensor must be installed after a filter.
3. The flow sensor installation has to avoid strong vibration and shaking of the environment, so as not to affect the sensor's measurement accuracy.
Features:
4. Copper material, environmental friendly material, small, flexible and functional.
5. Intubation design of inlet and outlet pipe, easy connection and operation;
6. Imported Hall IC from Japan, stable and reliable;
7. Range: 1-30L/min;
8. working voltage: DC3-18V;
9. rated voltage: DC5V;
I don't think that sensor can generate pulses, it's a hall element, so the output tension varies with the water-flow. Or you have to use the schematic i used for temperature readings (voltage to frequency IC = LM331) See also below in the measuring temperature topic.
10. Output voltage(rated: DC 5V); High level 4.5V and above; low level 0.5V and below
11. Pulse output duty cycle: 50+-10%
12. Insulation resistance: 100M Ohm and above;
13. Tightness: Seal up all the holes, and inflate with 1.7MPa water, after 1 minute, no leakage and deformation;
14. -20-80 Cel.degree;
Ohh, i messed with the comment in the specs between 9 and 10... cant change that anymore !
As the formula indicates it must be pulses; I bet, the hall element is not used proportionally to measure a magnetic field's strength, but works as a magnetic switch as replacement for a reed switch; there are hall sensors with built in Schmitt-trigger that deliver a "high" on magnetic field present and "low" if not...
To get the meter constant you now have to calculate what one impulse actually means - from the formula there is 2.1Hz at 1l/min and 237Hz at 30l/min...
If it is an impeller then one turn would equal one impulse and would have transported what volume through the cross-section of the flow channel?
Ok, Markus, it's correct that there are pulses, i didn't read it well, big mistake of me.
In the specs on point 10 and 11:
10. Output voltage(rated: DC 5V); High level 4.5V and above; low level 0.5V and below
11. Pulse output duty cycle: 50+-10%
I just wondering if the pulses are proportional and linear to the flow.