Sensor box containing one sensor and one signal condtioner with 4...20mA, 2-wire output



The SB1I is a pressure die cast aluminium sensor housing (IP65) with an integrated sensor for measuring uniaxial acceleration or inclination.
In addition to the sensor, the box contains a signal conditioner with 4...20mA, 2-wire output and a separate, highly stable supply voltage feeding off the current loop. Furthermore, the 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 coupling to the current loop. Interference signals caused by unwanted ground currents are avoided by electrically isolating sensor and signal conditioner from the housing. Unlike the SB2.., the SB1I can accommodate larger inclinometers, such as the NG-series, that have a higher measuring accuracy. A special electronic temperature compensation system can significantly reduce the temperature sensitivity of the implemented sensor.
The compact metal cable guide and small housing size in combination with the 2-wire connection enable the use of this high quality measuring system in harsh operating conditions.


The SB1I is suitable for applications requiring precise inclination or acceleration measurements under harsh circumstances and returning of a 4...20mA output signal. Areas of successful implementation include construction, mining, agricultural machinery, transportation and conveyor systems, ships, operation and automation technology as well as general mechanical engineering.

Technical Specifications

Terminals max.: 3 x 1.5 mm2
Cable fixing M12 x 1.5 cable gland, clamping range 6mm ... 7.5mm
Measuring range, Resolution, etc. dependents on implemented SEIKA sensor
Degree of protection IP65
Mounting orientation any
Measuring planes (N.. sensor) 3 main housing planes
Measuring plane (NG.. sensor) parallel to bottom of housing
Measuring directions (B.., BD.. sensor) X,Y,Z coordinates of housing
Terminal voltage 10V ... 30V
Minimum loop current 2.5mA ... 3.5mA
Maximum loop current 22mA ... 26mA
Output signal loop current 4mA ... 20mA (12mA for sensor zero position)
Adjustable variables zero point (12mA), amplification
Maximum load resistance 500 Ohm (for 24 Volt supply voltage)
Operating temperature -40...+85°C

Options: special measuring ranges, calibration record, silicon encapsulation, custom wiring

Dimensions of SB1I containing NG inclinometer


Since the SB1I supply voltage feeds off the current loop (the SB1I requires 3mA at most), a voltage of 10V across the SB1I terminals must be guaranteed to ensure correct functionality even for the maximum loop current of 24mA (maximum voltage drop across transmission line and load resistance).

Dimensions and Measuring Directions of SB1I with N inclinometer

The above diagrams demonstrate the feasibility of measuring most angles of inclination and directions of acceleration with SEIKA cased sensors. The resulting multitude of different possibilities do make choices difficult. We'd be glad to give you advice on putting together the components best suited for your measurement task and are happy to receive your information on what planes and directions the inclinations and/or accelerations are to be measured. A sketch of your situation is often very handy.


SEIKA Mikrosystemtechnik GmbH - Söllerweg1- D 87487 Wiggensbach - email: - Tel.+49 8370 9290070 - FAX:+49 8370 9290079