Description
The QSKA is a calorimetric flow switch for water, oil and air with no moving parts in the medium. It is particularly suited to water, cutting fluid, lubricating oil and air, and to pump dry-running protection.
A heated and an unheated resistor in the probe sense the flow velocity. Setting range: 1 … 150 cm/s water, 3 … 300 cm/s oil, 20 … 2000 cm/s air, by potentiometer. Accuracy and repeatability of the switching point are not documented. Output PNP, NPN or relay (SPDT), switching current ≤ 400 mA (PNP/NPN) or ≤ 4 A (relay). Supply 24 V DC ± 20 % or 230 V AC ± 15 %, response time 1 … 13 s, typically 2 s. Connection via M12 × 1 plug or 2 m of cable.
Probe in stainless steel, housing in PBT. Process connection G1/2, G1/4, R1/2 or R1/4 male or M18 × 1.5 female, probe length 30 mm (DN32 and below) or 50 mm (DN40 and above). Pressure rating 100 bar, medium temperature -20 … +80 °C, protection IP67. A declaration of conformity is not documented in the datasheet. Before sizing, note: The setting range is a flow velocity; the flow rate depends on the pipe bore. The pressure of the installed assembly is set by the accessory; the conventional stainless tee is rated 40 bar. For the relay (4 A) neither a voltage nor an AC/DC rating is documented.
Advantages at a glance
- Calorimetric principle with no moving parts
- Settable for water, oil and air
- Output PNP, NPN or SPDT relay
- Supply 24 V DC or 230 V AC
- Pressure rating 100 bar at the switch
- Protection IP67
- LED row with six LEDs for switching state and velocity trend