How do you calculate leak test workload?

Divide the number of assemblies by the leak tests completed per hour to get base hours, then multiply by one plus the allowance. For 60 assemblies at 6 per hour with a 30% allowance, base is 10 hours and required workload is 13 hours.

What does the evacuation and retest allowance cover?

It captures time that the raw test rate ignores: pulling and holding vacuum, letting the helium or pressure signal stabilize, and re-running borderline or failed units. Thirty percent here adds 3 hours on top of the 10-hour base.

What is a typical leak test rate per hour?

It depends on method and circuit size — pressure-decay can run faster than mass-spectrometer helium testing, which needs evacuation. Six assemblies per hour is a reasonable mid-range for a manned helium bench on medium circuits.

Why not just divide assemblies by test rate?

Because the base 10 hours assumes back-to-back tests with no vacuum pull-down, no signal settling and zero retests. The 30% allowance turns that ideal into a schedulable 13 hours that reflects how the bench actually runs.

How do I reduce leak test workload?

Attack the allowance and the rate together: faster evacuation pumps and pre-evacuation fixtures cut stabilization time, while reducing upstream braze and flare defects cuts retests. Both shrink the gap between the 10-hour base and the 13-hour requirement.

Helium vs pressure-decay leak testing for workload?

Pressure-decay usually tests faster (higher rate, lower allowance) but is less sensitive; helium is slower because of evacuation and settling but catches finer leaks. Set the rate and allowance to match whichever method the bench uses.

Industrial Heat Pumps & Electrified Thermal Systems calculator

Heat Pump Leak Test Workload Calculator

Leak Test Workload converts a batch of heat pump circuits or assemblies into the labor hours required to leak test them, including the real-world overhead of evacuation, pressure stabilization and retesting suspect units. Quality and production planners use it to staff helium and pressure-decay leak benches and to schedule them against the day's build. It matters because leak testing on refrigerant circuits is slow and uneven — a sensitive helium test needs a deep vacuum and a stable signal, and any borderline unit gets re-run — so the raw count of assemblies badly understates the time needed. This calculator surfaces that hidden overhead before it derails the schedule.

What this calculator does

Estimate technician or bench hours required for leak testing heat pump circuits and thermal assemblies from scope count, throughput, and retest allowance.
Use it when a quality engineer or production planner needs to load helium, nitrogen, vacuum hold, or hydro test resources for heat pump circuits, coils, or packaged skids.
It computes required leak test workload in hours by dividing the assembly count by the test rate, then inflating for an evacuation, stabilization and retest allowance.

Formula used

Base leak test workload = circuits or assemblies to leak test ÷ leak tests completed per hour
Required leak test workload = base leak test workload × evacuation, stabilization, and retest allowance

Inputs explained

Circuits or assemblies to leak test:
Leak tests completed per hour:
Evacuation, stabilization, and retest allowance:

How to use the result

Use it when staffing or scheduling leak test benches for a known batch of circuits or assemblies.
The allowance is a single average percentage, so a batch with an unusual cluster of leakers or a deep-vacuum requirement can blow past the planned hours.

Current U.S. benchmarks

Global copper trades at $13,484 per tonne (IMF via FRED, May 2026), up 41.5% in a year, and U.S. industrial electricity averages 8.66 cents per kWh. Both feed electrified-hardware unit economics.
The U.S. has 21,668 machinery manufacturing establishments employing about 1,086,146 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate leak test workload? Divide the number of assemblies by the leak tests completed per hour to get base hours, then multiply by one plus the allowance. For 60 assemblies at 6 per hour with a 30% allowance, base is 10 hours and required workload is 13 hours.
What does the evacuation and retest allowance cover? It captures time that the raw test rate ignores: pulling and holding vacuum, letting the helium or pressure signal stabilize, and re-running borderline or failed units. Thirty percent here adds 3 hours on top of the 10-hour base.
What is a typical leak test rate per hour? It depends on method and circuit size — pressure-decay can run faster than mass-spectrometer helium testing, which needs evacuation. Six assemblies per hour is a reasonable mid-range for a manned helium bench on medium circuits.
Why not just divide assemblies by test rate? Because the base 10 hours assumes back-to-back tests with no vacuum pull-down, no signal settling and zero retests. The 30% allowance turns that ideal into a schedulable 13 hours that reflects how the bench actually runs.
How do I reduce leak test workload? Attack the allowance and the rate together: faster evacuation pumps and pre-evacuation fixtures cut stabilization time, while reducing upstream braze and flare defects cuts retests. Both shrink the gap between the 10-hour base and the 13-hour requirement.

Last reviewed 2026-05-12.