How to Choose a Vibration Sensor for Hot Runner Systems

Four important factors should be considered when choosing a vibration sensor for a hot runner system: temperature resistance, size, output, and accuracy. You can select an appropriate model by adhering to following guidelines:

1. Temperature Resistance Matching is the first essential need.

The usual operating temperature range for hot runners is 150–300°C. The maximum working temperature of the hot runner must be at least 20°C lower than the highest temperature resistance of the sensor.

Select a model with a temperature resistance of at least 250°C for regular hot runners. Select a model with a temperature resistance of at least 350°C for high-temperature hot runners (processing engineering plastics).

A conventional room-temperature sensor should never be used since high temperatures will quickly cause the sensing element to burn out, resulting in data drift and failure.

2. Compatibility of Size: Compact Installation Size

Installations of hot runners are frequently limited in area. Give small-volume packages-typically M5/M8 threaded packages-priority in order to prevent interference with the heating coil and manifold channel. Select a model with a smaller diameter for multi-point monitoring to make arrangement simpler.

3. Output and Integration Adaptation: Injection molding systems must be integrated with factory MES systems and injection molding machine PLCs. Models with standard signal output (RS485/4-20mA analog output) should be given priority for straightforward integration without the need for further conversion modules. To counteract the effect of high temperatures on measurement accuracy and avoid zero-point drift, use models with temperature compensation for high-end applications.

4. Accuracy Matching: It is sufficient to meet the requirements. An accuracy of 0.01mm is adequate for routine defect notifications and bulk production monitoring. Choose high-precision models with an accuracy of at least 0.001mm for R&D analysis and precision injection molding.

5. Brand and Price Selection: Domestic brands are chosen for cost-effectiveness; Hanwei Technology and Kunlun Coast's high-temperature resistant MEMS sensors are roughly 40% less expensive than foreign ones, satisfying the majority of mass production requirements. Select foreign brands for high-end precision injection molding: American PCB high-temperature type and Keyence SR series provide greater accuracy and long-term stability, making them appropriate for high-end applications like medical and 3C devices.