Overview
ISO 21360-2:2020 - Vacuum technology - Standard methods for measuring vacuum-pump performance - Part 2: Positive displacement vacuum pumps defines standardized test methods for assessing the performance of positive displacement vacuum pumps (and other pumps that discharge against atmospheric pressure, e.g. drag pumps). It complements ISO 21360‑1 by applying the general measurement principles to pumps with swept volumes and specifies how to measure volume flow rate, base pressure, water vapour tolerance, power consumption, and the lowest start‑up temperature.
Key topics and technical requirements
- Volume flow rate: Uses the throughput method (preferred) or the pump‑down method. Test dome sizing is specified (e.g., ≥2·VSW for rotary plunger and fixed‑vane types; ≥5·VSW for other types). Measurement methods reference ISO 21360‑1 procedures.
- Base pressure: Measured with the same experimental setup as volume flow rate. Measurements shall be made with and without gas ballast where applicable.
- Water vapour tolerance and capacity: Defines water vapour tolerance (maximum water vapour partial pressure that can be conveyed without condensation) and provides example measurement and calculation methods in Annex A and B. Annex C includes a table of water saturation vapour pressures.
- Power consumption: Specifies conditions and procedure for measuring real electrical power. Key points:
- Measure at base pressure (with and without gas ballast) and at maximum power consumption.
- Use a power meter between mains and pump (frequency filters allowed for electronic supplies).
- Record three measurements over 15 minutes and report mean or maximum as specified.
- Lowest start‑up temperature: Procedure to determine the minimum temperature at which the pump will start and reach 80% nominal speed within 10 minutes. Special provisions for pumps that must start under vacuum.
- Operating conditions and uncertainty: Rotational frequency tolerance (±3% if not otherwise specified), run‑in periods to reach thermal equilibrium, and guidance to determine measuring uncertainties per ISO 21360‑1.
Practical applications and users
Who uses ISO 21360-2:2020:
- Manufacturers of positive displacement vacuum pumps for product development, performance validation, and technical datasheets.
- Test laboratories and certification bodies for reproducible performance testing and compliance evaluation.
- R&D and quality control teams seeking standardized methods to compare designs or production lots.
- Purchasing/procurement specialists and end users (laboratories, semiconductor, coating, HVAC, packaging industries) who need reliable performance data (flow, base pressure, water vapour tolerance, and power use) to select appropriate pumps.
Practical value:
- Ensures repeatable, comparable performance data across suppliers.
- Helps size pump systems, assess compatibility with condensable vapours, and estimate energy consumption under specified inlet conditions.
Related standards
- ISO 21360‑1:2020 - General description and baseline measurement methods (normative reference).
- Referenced literature and annexes within ISO 21360‑2 cover calculation examples and vapour tables for accurate conversions between tolerance and capacity.
Keywords: ISO 21360-2:2020, vacuum technology, positive displacement vacuum pumps, volume flow rate, base pressure, water vapour tolerance, power consumption, standard methods, pump testing.