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 600 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. The S-230 accelerometer is packaged as a borehole 3-component unit (Model PA-23BH) and as a surface 3-component unit (Model PA-23). PA-12 can be submerged up to 100 m depth. Mounted inside the SMART-24A™ data logger, a 24-bit Strong Motion Recorder is obtained.

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
- 2.5 V/g, factory adjustable to other values
- -20 to +65 ºC (-4 to +145 ºF)
- 1% of Full Scale (defined as the maximum deviation of the sensor's transfer function from a straight line through the end points at full scale, expressed as a percentage of the full scale)
- >130 dB between 0.03 and 10 Hz
- Electromagnetic, 1g/V
- 10 microg rms (non-coherent)
- ±4.2 g
- 0.01 g/g maximum
- +12 VDC

PHYSICAL CHARACTERISTICS - BOREHOLE PACKAGE (PA-23BH)

Dimensions
Height
Diameter
Net Weight
Casing

- 30 cm (11.8 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