You can have this done to your new instrument or an existing one. The Model 650 has a different design to accommodate large samples such as Banana. It has triple start threads on the chamber cover that permits rapid measurements with a minimum of effort. The cover can be screwed in place by rotating it 720 degrees. The 650 does not need nor have a cover safety valve.
Inserts are available to change the cover hole size.
A precision rate control valve permits accurate and consistent control over the rate of pressure increases in the chamber while a large precision gauge gives accurate and precise pressure measurements. All instruments have a pressure relief valve that prevents over pressurization. Each gauge is checked for proper calibration before it is installed. The model 610 has a 22 cubic foot tank built into its aluminum case. This combination makes a lightweight and compact instrument for field use.