This is a vacuum systems product and is not covered in this discussion. I will forward your question to that group.
Here is an answer I received directly from the vacuum division:
The “spec tube” error is because the system has not achieved a proper
vacuum. It could be because the roughing pump is not running, or the test port
thermocouple is bad.
In the U.S., you can contact the Vacuum Division directly 800 882-7426, option 3