Special Topic on Petroleum Logging Instruments— (core parts) Quartz Flexible Accelerometer

Quartz flexible accelerometers are single-axis gravity accelerometers, which are characterized by simple structure, small size, high accuracy and sensitivity, and high reliability. Its internal structure diagram is as follows.

The working principle of the quartz flexible accelerometer is that when the inertial mass is subject to external acceleration, the relative position shifts slightly, the change in the distance between the differential capacitor plates causes a change in the differential capacitance. The servo amplifier detects this change and outputs the corresponding current, sending to the coil located inside the magnetic field, produces a feedback torque that is balanced with the input acceleration torque, the inertial mass returns to its equilibrium position again. By measuring this current signal, the input acceleration can be calculated.

The quartz flexible accelerometer is composed of a meter head and a servo circuit. The quartz flexible accelerometer used in the inclinometer tube is innovatively optimized for the meter head and servo circuit.

The meter head includes the inspection quality assembly and the upper torque converter assembly. Among them, the main problem that affects the high-temperature working life is the connection between the terminal and the gold-plated film of the quartz pendulum. the method generally adopted by manufacturers is to use soldering to connect, because there is a problem of tin corrosion of the gold film, high temperature operating life and vibration resistance will be affected. The difference from ordinary quartz meters is that gold wire bonding is used to connect the IC chip to the package pins to enhance reliability and longevity.

The servo circuit includes a differential capacitance detector, integrator, and compensation amplifier. Our factory improves performance for long-term reliability in a high-temperature working environment of 175°. Compared with ordinary plastic packaging process chips, the multi-chip module thick film hybrid integrated circuit process is used to solve the problem of being unable to work in a high temperature environment of 175° for a long time.