Heat Treatment, Furnaces & Thermal Processing worked example

Hardness Variation at 66% hardness tester uptime: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop hardness tester uptime to 66%, then walk the calculation through step by step. Estimate hardness inspection capacity for variation checks from readings per setup, test cycles, tester uptime, and accepted reading yield.

The inputs for this scenario

  • Hardness readings per test cycle: 12 readings / cycle (held at the documented default)
  • Available hardness test cycles: 40 cycles / shift (held at the documented default)
  • Hardness tester uptime: 66 % (the input this scenario stresses; the baseline uses 92)
  • Accepted hardness reading yield: 98 % (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Gross hardness reading capacity = readings per test cycle × available hardness test cycles.
  • Accepted hardness reading capacity works out to 310 readings / shift at these inputs, and this is the headline figure for the scenario.
  • Gross hardness reading capacity works out to 480 readings / shift at these inputs.
  • Tester downtime loss works out to 163 readings / shift at these inputs.
  • Rejected reading loss works out to 6.34 readings / shift at these inputs.

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 28.26% below the baseline at 310 readings / shift.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to hardness tester uptime, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. 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: 310 readings / shift (headline result)
  • Gross hardness reading capacity: 480 readings / shift
  • Tester downtime loss: 163 readings / shift
  • Rejected reading loss: 6.34 readings / shift

Run it with your numbers

  • To rerun this with your own numbers, open the live Hardness Variation calculator, set hardness tester uptime to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.