Appropriate Sensor Clearance…

This question highlights an often overlooked concern when using pressure sensors mounted underneath ejector pins.

How much of a gap should be used between the pressure sensor and the ejector pin?

My Response
The general recommendation from most manufacturers is between 0.25-0.5mm or 0.010-0.020in.
In reality, this specification refers to the clearance between the top of the ejector pin head and the counter-bore in the ejector plate. Most mold makers use a similar ejector pin clearance even when a sensor is not being used.
Additional Thoughts
The purpose of this clearance is to ensure there is no preload on the sensor, especially if any dirt gets beneath the sensor. Such a preload will destroy the sensor and provide erroneous pressure readings.

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