Description
The QGKL is a thermal mass flowmeter for gas in stainless steel with colour LCD and thread connection for nominal sizes DN15 … DN50. It is particularly suited to nitrogen and air, oxygen or hydrogen, as the datasheet gives a separate flow range for each of these gases.
Thermal diffusion principle with a heated and an unheated resistance thermometer. Flow range 5 … 705 m³/h by size and gas, for oxygen about half, for hydrogen less than a tenth of the air range. Dead band ≤ 0.1 m/s. Accuracy ≤ 1.5 %, no reference stated, response time 1 s, adjustable. Outputs by version: two switch outputs, PNP, NPN on request, with linear pulse 100 Hz, plus 4 … 20 mA or 1 … 5 V, alternatively RS485. Supply 18 … 30 V DC. Connection via M12 plug, colour LCD on the device.
Body of stainless steel 304, stainless steel 316 as an option and intended for hydrogen, display housing of engineering plastic. Process connection G1/2 … G2 as external or internal thread, working pressure ≤ 2.5 MPa with external thread and ≤ 4.0 MPa with internal thread. Medium temperature -20 … +80 °C, protection grade IP65. Explosion protection is not documented. A declaration of conformity is not documented in the datasheet. Before sizing, note: the technical data give 18 … 30 V DC, both wiring diagrams 12 … 30 V DC. The velocity of up to 100 m/s does not match the range table in m³/h; the table applies. There is no moulded cable socket for the four-core RS485 version.
Advantages at a glance
- Separate ranges for nitrogen and air, oxygen and hydrogen
- Stainless steel 304, optionally 316
- Up to 4.0 MPa with internal thread
- Protection grade IP65
- Colour LCD with flow, velocity and total
- Two switch outputs plus analogue output or RS485
- Dead band ≤ 0.1 m/s
- Nominal sizes DN15 … DN50, thread G1/2 … G2