SM2i-B: Sensor box (2-axis accelerometer) - Output signal 4-20mA

The SM2i-B is a pressure die cast aluminium sensor housing (IP65) with two integrated sensors for measuring accelerations along two axis.
As well as the sensors, the box contains two independent signal conditioners, each with a 4...20mA, 2-wire output, and two separate, highly stable voltage supply feeding off the corresponding current loop, one for each sensor.
Furthermore, each signal conditioner includes an active low pass filter, whose upper cut-off frequency / settling time can be adjusted to suit the measurement task, an output stage with current limitation, a noise voltage filter and a diode bridge for unipolar connection to the current loop. Interference signals caused by unwanted ground currents are eliminated by electrically isolating each sensor and signal conditioner from each other and the housing.

A special electronic temperature compensation system can significantly reduce the temperature sensitivity of the implemented sensors. The compact PG cable gland and small housing size in combination with the 3-wire connection enable the use of this high quality measuring system in harsh operating conditions.