Guralp Systems Limited

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1. Introduction 2. Assembling the instrument 3. Installing the 40TB in a borehole 4. Calibrating the 40TB 5. Connector pinouts 6. Connector pinouts 7. Specifications 8. Revision history

Chapter 7. Specifications

Velocity sensors

Velocity output bandwidth

spec – 100 Hz*

 

Mass position output

DC – spec Hz*

 

Velocity sensitivity

2 × 1000 V/m/s**

 

Mass position sensitivity

1000 V/m/s2

Controls

Mass locking and unlocking

remotely operated

 

Mass centring

automatic, microprocessor controlled

Mechanics and electronics

Sensors

3 orthogonal sensors, each 0.180 kg

 

Lowest spurious resonance

above 140 Hz

 

Sensor transducer type

capacitive displacement

 

Feedback transducer type

magnet/coil

Connector

pressure tight, waterproof

Borehole diameter

89 – 229 mm

 

Temperature range with masses locked

–20 to +75 °C

 

Operational temperature range

–10 to +65 °C

Power

Supply requirements

12 – 30 V DC

 

Current at 24 V DC

75 mA†

*spec refers to the quoted frequency response value, e.g., for a “30 s” sensor, the value of spec would be 30 s = 0.033 Hz.

**Sensors are available with a range of sensitivities between 2 × 750 and 2 × 10,000 V/m/s.

PreviousNext

1. Introduction 2. Assembling the instrument 3. Installing the 40TB in a borehole 4. Calibrating the 40TB 5. Connector pinouts 6. Connector pinouts 7. Specifications 8. Revision history