ASTM A833 refers to comparison hardness testing, and it is based on the Brinell hardness testing principle described in ASTM E10. This would include Poldi and Telebrineller testers.
Although Poldi operates by this principle you need to confirm what the ball is made of on your tester. The ASTM spec states that balls shall be made from hardened steel. Some Poldi testers use tungsten carbide.
Blocks need to be standardized per ASTM E10. You need to confirm where your blocks came from.
Finally, as cloa has stated, you need to buy the spec. There are several other guidelines with regard to conducting the test that you need to be aware of before proceeding.