See the below link to a file that provides instructions to use TEST port adapters that come with deadweight testers, comparators, E-DWT 6531 and E-DWT 6532. The document also shows what parts are included.
Here's an example of a 1/4 inch NPT female adapter on top of the TEST port of a P3000 deadweight tester with a 2700G digital gauge screwed into the top of the adapter.
Note: New P3100 deadweight testers include PK-P3000-ADPTR-STD kit
The P3100 adapter kits are fully backwards compatible with older bases (except 38xx). The older test ports used a bonded seal instead of an o-ring to seal on it, but the internal geometry on the adapters is the same. See this article for information on the TEST port seals for current models, Deadweight TEST port o-rings. A link to an article for older deadweight testers is in that article also.
Part Number: 4185780
Description: PK-P3000-ADPTR-STD, ADAPTER SET, P3000 STANDARD, MWP 140 MPA (20,000 PSI)
Includes these adapters: 1/8 BSP, 1/4 BSP, 3/8 BSP, 1/2 BSP, 1/8 NPT, 1/4 NPT, 1/2 NPT, 3/8 NPT, M20 X 1.5, M14 X 1.5.
If you have a PK-3000-ADPTR adapter kit and want to use it with an E-DWT (or other product with a high pressure DH500 port) you will also need the adapter kit in the red box above. This is:
Part Number: 4294865
Description: PK-DH500-P3000,DH500 TO P3000 TEST PORT ADAPTER, MWP 140 MPA (20,000 psi)
It includes all adapters in kit 4185780 also.
Contact Fluke Calibration Pressure Technical Support at the below link or by calling +1.877.355.3225