Heat Treatment, Furnaces & Thermal Processing worked example

Hardness Variation at 99% hardness tester uptime: a worked example

What does the result look like when hardness tester uptime reaches 99%? The full calculation is worked below with real intermediate numbers. Use it when Rockwell, Brinell, Vickers, or microhardness checks are limiting release of heat treated lots.

The inputs for this scenario

  • Hardness readings per test cycle: 12 readings / cycle (unchanged)
  • Available hardness test cycles: 40 cycles / shift (unchanged)
  • Hardness tester uptime: 99 % (raised for this scenario; the documented default is 92)
  • Accepted hardness reading yield: 98 % (unchanged)

Working through the calculation

  • Applying the documented formula (Gross hardness reading capacity = readings per test cycle × available hardness test cycles) to the inputs above produces each figure below.
  • At this operating point the engine returns 466 readings / shift for accepted hardness reading capacity, the number this scenario is built around.
  • At this operating point the engine returns 480 readings / shift for gross hardness reading capacity.
  • At this operating point the engine returns 4.8 readings / shift for tester downtime loss.
  • At this operating point the engine returns 9.5 readings / shift for rejected reading loss.

How this compares with the baseline

  • Against the tool's baseline example, where hardness tester uptime sits at 92% and the headline result is 433 readings / shift, this scenario comes in 7.61% above the baseline at 466 readings / shift.
  • A figure at this level is achievable when hardness tester uptime is genuinely sustained, not just peaked for a shift. It models steady-state capacity; it does not capture operator-to-operator variation in reading technique or the time lost to recalibrating between scales (Rockwell C to B, for example).

Results at a glance

  • Accepted hardness reading capacity: 466 readings / shift (headline result)
  • Gross hardness reading capacity: 480 readings / shift
  • Tester downtime loss: 4.8 readings / shift
  • Rejected reading loss: 9.5 readings / shift

Run it with your numbers

  • Every input above is editable in the live Hardness Variation calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.