Dear sir,

I have a DT85, can you help my how to measure the pressure and flow rate by using pressure transducer?

Sensor model:

• VEGABAR 14 http://www.vega.com/downloads/PI/EN/37527-EN.PDF
• Flow meter turbine model :http://www.gemssensors.com/Products/Flow/Electronic-Flow-Sensors/Turbo-Flow/FT-110-Series-Flow-Sensor

I would like to know that I need external circuits or connect it directly with the data logger.

Regards,
Mohamed

Good morning Mohamed,

The pressure transducer is a simple 4 to 20 mA output. Depending on your application configuration C2 on page 238 of the DT80 manual (UM0085-B3) would probably be best. You will need an external 12 VDC power supply and a shunt resistor.

The flow sensor is a hall effect device. This connects to one of the High Speed Counters. You will need to use the low threshold option to read the hall effect output.

Cheers,
Roger

Dear Roger,

Thanks for your reply, I followed your notes.

I connected the flow meter turbine with high speed counter (C1), it is working but the problem is that the counter read pulse and no flow rate, I don't know why? Also the pulse not fixed with the same flow rate, and it's increasing with the time, is their are any things I must do it in the data taker setting?

Regards,
Mohamed

Good morning Mohamed,

The sensor is most probably reading out in x number of pulses per litre. If you divide the reading by the time interval then you have flow rate.

If you use the RS channel option (Reading / time) then you will have flow rate in seconds.

Cheers,
Roger