Piezoelectric Cavity Pressure Sensor Setup in Micro Injection Moulding
Direct piezoelectric cavity pressure sensing in micro injection moulding requires sub-micron bore tolerances, rigid preloading, and active thermal drift compensation.
High Impedance Coaxial Cable
Meaning
Transmission lines designed with elevated dielectric electrical resistance prevent charge leakage during low-current piezoelectric pressure measurement. Piezoelectric cavity sensors in injection moulding tools output minute electrostatic charges measured in picocoulombs per bar. A high impedance coaxial cable routes these tiny electrical signals from mold embedded sensors to external charge amplifiers without signal attenuation.
Standard coaxial cables allow rapid dissipation of electrostatic charges through low insulation resistance layers. Maintaining electrical resistance above ten teraohms ensures accurate pressure readings during extended holding phases.
Charge Transport
Piezoelectric quartz elements generate electrical charge under mechanical force without external power sources. High insulation resistance along the conductor path prevents charge leakage to ground during static holding cycles. Connecting a high impedance coaxial cable preserves charge integrity between sensor terminals and amplifier inputs.
Contamination within cable connectors lowers surface resistance, causing signal drift during pressure monitoring.
Noise Immunity
Moulding shops contain electromagnetic interference from high-power heaters and electric drive motors. Braided metallic shielding surrounding the dielectric layer reflects external electromagnetic noise away from inner signal conductors.
Signal Integrity
Moisture or oil ingress inside cable shielding degrades insulation performance. Compromised high impedance coaxial cable insulation distorts peak pressure records, triggering false alarm thresholds on machine control units.