CET7701B6CH Charge Amplifier for Weigh In Motion System

CET7701B6CH charge amplifier is a 6-channel charge amplifier whose output voltage is proportional to the input charge. Equipped with piezoelectric sensors, can measure the acceleration, pressure, force and other mechanical quantities of objects, widely used in water conservancy, power, mining, transportation, construction, earthquake, aerospace, weapons and other sectors. This instrument has the following characteristics:
The main components with reasonable structure are high import precision, low noise and small drift, so the quality is stable and reliable.
Eliminate the attenuation of the equivalent capacitance of the input cable to the signal, can connect to the cable without affecting the measuring accuracy;
For a dynamic weighing system, the charge amplifier adapts to the vehicle's speed range of 0. 5-100 km/h.

Charge amplifier front panel

Charge amplifier right view

Dimensions for CET7701B-6CH charge amplifier

Technical Parameters
Input characteristics: maximum input charge ±130000Pc; Sensitivity: 0.05mV / Pc;
Frequency response:
      (a) Upper frequency: 100kHz (- 3dB ±1dB);
      (b) Lower limit frequency: 10Hz (- 3dB ±1dB);
Output properties:
      (a) Maximum output amplitude: +6.5 VPP;
      (b) Max output current: table +50 mA;
      (c) Output resistance: less than 10 ohms;
      (d) Distortion: less than 0.5%;
Noise: less than 1 mV;
Working power supply: 24VDC + 20%, ≤35mA;
Level of protection: IP65 (panel);
Accuracy: less than 1% (under rated working conditions, ±6.5 VPP, 160Hz sine signal measurement);
Working temperature:-40 ℃ ~ 80 ℃;
Number of channels: 6;

Use Methods
      1. The charge amplifier input impedance is extremely high, in order to protect the body or the external induced voltage breakdown of the input amplifier, when connecting the sensor to the charge amplifier input, removing the sensor, or suspecting loose connector, checking tightening, the power supply must be turned off. 
       2. Although the equipment can match the extension cable, the long cable will introduce noise, such as the inherent noise, mechanical movement and induced AC noise of the cable. Therefore, when on-site measurement, the low-noise cable shall be adopted and shall be fixed as short as possible, and be far from the large power equipment of the power line.
      3.  Welding and assembly of connectors to sensors, cables and charge amplifiers are highly professional and should be repaired by specialized technicians. After welding, apply rosin anhydrous ethanol solution (welding oil prohibited), apply medical cotton ball to clean flux with anhydrous alcohol (medical alcohol prohibited), and dry. The connector should be kept clean and dry, and the shield cap should be screwed when it is not in use.
      4. In order to ensure the accuracy of the instrument, the measurement should be preheated for 15 minutes. If humidity exceeds 80%, preheating time should be more than 30 minutes.

Wiring Instruction

Charge Amplifier signal output, power connection diagram

Charge Amplifier signal input wiring diagram