Description
The LWMA is a gas cylinder scale for continuous operation: the liquefied gas cylinder stays on the scale permanently, with display, limit values and overload protection built in. It is suitable for weight and level measurement in the industrial sector, for example to see in good time when a cylinder needs to be changed.
The scale measures the weight on a round weighing platform and outputs it as 4 … 20 mA with superimposed HART signal on the 2-wire current loop, supplied with 12 … 40 VDC from the loop. Two electronic PNP limit value contacts (30 VDC, 200 mA) switch with freely adjustable switching point, hysteresis and delay, galvanically isolated from the measuring amplifier. The 4-digit red LED display shows the reading right at the scale and stores minimum and maximum. Settings are made with three keys or by software via HART. The measuring amplifier works with 16 bit and 10 measurements/s, linearises over up to 10 points and has a total error of 0.3 % of range, the load cell 0.02 % of range.
Available with 250 kg (platform Ø 245 mm, height approx. 80 mm, approx. 7 kg) and 500 kg (platform Ø 410 mm, height approx. 95 mm, approx. 19 kg). Weighing and base plate are made of zinc-plated steel, the overload protection is adjustable via three locking rings, and the load cell withstands 120 % overload and 150 % breaking load. Connection is via 2 × M12x1, 5-pin, which also allows several scales to be connected together, with a separate 4 … 20 mA signal per scale and the limit value contacts wired in parallel. Protection is at least IP65 with connections plugged, the operating range −20 … +55 °C.
Advantages at a glance
- For continuous operation, the cylinder stays on the scale
- Rated load 250 kg or 500 kg
- 4 … 20 mA HART, 2-wire current loop, 12 … 40 VDC
- Two PNP limit value contacts with LED, galvanically isolated
- 4-digit LED display, can be mirrored by 180°, min./max. memory
- Overload protection adjustable via three locking rings
- Several scales can be connected together via 2 × M12x1
- Protection at least IP65, operating range −20 … +55 °C