A customer recently asked this question regarding mold temperature…
What is the best method for measuring mold temperature? Should I trust the thermolator measurement?
When measuring mold temperature, it is actually best to measure these two factors… coolant temperature into the controller and coolant temperature out of the controller. If these are documented when the process is molding acceptable parts, then you can better replicate the conditions in the future.
These measurements should be taken using a surface probe in contact with the in and out connectors of the temperature controller.
The return temperature provides a good indication of the mold temperature. The difference between these two numbers provides a good indication of cooling effectiveness. Higher differences may indicate a poor coolant flow, while a low difference may indicate a too much coolant… or an improperly connected coolant line.
Some molders use the thermolator measurements with good success… but these measurements should be calibrated and verified often with a pyrometer with a surface contact probe.
Mold surface temperature measurements can be helpful, but do not provide relevant data about the overall effectiveness of the mold temperature controller.