Operating Instructions MBA888
Operating Instructions MBA888
11/2017/Item No. 8001705
Page 3/6
MBA Instruments GmbH
5.
Function and switching behaviour
A motor rotates a shaft, with a vane secured to the end of the shaft. If the vane strikes the bulk material, a
torque builds up until the shaft stops rotating. The shaft then reverses its direction of rotation. The signal
switches when shaft rotation is blocked in both directions.
"Quick Switch" device design:
On this version, the MBA888 checks whether shaft rotation is blocked in one direction only. This means that the
very fast switching allows the device to be used as a "Full" indicator
:
6.
Installation
The MBA888 is screwed into a suitable sleeve with the process connection. The installation position must be selected
such that the vane at the end of the shaft is covered by the bulk material at the switching point. Light-weight or fluid
bulk material must cover the vane a little more than is the case with heavy bulk material. Measurement is
independent of the MBA888's installation position.
2. Shaft
stops
3. Shaft
turns CW
4. Shaft stops
Signal switches: "full"
1. Shaft
turns CCW
+3 s
+3 s
5. Shaft turns CCW
Signal switches: "empty"
+3 s
2. Shaft
stops
3. Shaft stops
Signal switches: "full
1. Shaft
turns CCW
+1s
4. Shaft stops
Signal switches: "empty"
+1s
light-weight bulk mat.
medium-weight bulk mat.
heavy bulk material
Examples
Washing powder
Barley
Plastic granulate
Quartz sand
Gravel
4 Mounting surfaces for
65 mm width across flats
Tightening torque: 300 Nmm
Screw-in sleeve: G1.5" to ISO 228/1
Container
wall
Equipotential bonding:
for equipotential-bonding
screw with eyelet, d = 4 mm
Container top section
