Force Balanced Accelerometer

Model PA-23, PA-23BH, S-230

2.5 V/g sensitivity
No maintenance
Excellent stability over long periods of time
Based on PA-22, more than 800 three-component units in operation in Taiwan Strong Motion Network

The Geotech Model S-230 is a high resolution, 1-component, force balanced accelerometer capable of meeting the noise and stability requirements of the most demanding seismic studies. It features a very wide frequency response (DC to 90 Hz) and an internal calibration coil. Three S-230 accelerometers are packaged as a borehole 3-component unit (Model PA-23BH) and as a surface 3-component unit (Model PA-23). PA-23BH can be submerged up to 100 m depth. The same accelerometers are mounted inside the SMART-24A®, a 24-bit Strong Motion Recorder.

TECHNICAL SPECIFICATIONS

OPERATING CHARACTERISTICS

Mode of Operation
Frequency Response
Full Scale
Sensitivity
Temperature Range
Linearity
Dynamic Range
Calibration
Noise level
Clipping level
Cross axis sensitivity
Power Requirements

- Vertical and horizontal
- DC to 100 Hz
- ±4.0 g (±2.0 g,±1.0 g,±0.5 g also)
- 2.5 V/g, factory adjustable to other values
- -20 to +65 ºC (-4 to +145 ºF)
- better than 0.2%
- total 148 dB
- Electromagnetic, 1g/V
- less than 1 microg rms (non-coherent)
- ±4.2 g
- 0.01 g/g maximum
- +12 VDC (10V - 36V)

PHYSICAL CHARACTERISTICS - BOREHOLE PACKAGE (PA-23BH)

Dimensions
Height
Diameter
Net Weight
Casing

- 68.6 cm (27.0 in.)
- 8.9 cm (3.5 in.)
- 4.8 kg (10.6 lbs.)
- Waterproof, submersible to 100 m

PHYSICAL CHARACTERISTICS - SURFACE PACKAGE (PA-23)

Dimensions
Length
Width
Height
Net Weight
Casing

- 25 cm (9.9 in.)
- 15 cm (6.0 in.)
- 10 cm (4.0 in.)
- 4.8 kg (10.6 lbs.)
- Waterproof