# What daily checks does a PSA plant operator do?

**What should a PSA oxygen plant operator check every day?**

Every day the plant runs, a PSA operator inspects the plant and records its key readings: the Global Fund daily checklist covers ventilation, filters, compressor oil, condensate drains and the backup manifold, then room and compressor temperature, dew point, oxygen purity on the PLC and on a handheld analyser, alarms and running hours.

The Daily Maintenance Checklist written by Build Health International for the Global Fund's Project BOXER (2025) is meant to be completed each day the plant is operated, initialled by the technician, and kept separately for each system of a duplex or triplex plant. It is designed to be adapted to the specific plant, and Global Fund guidance links it to the early identification of critical malfunctions.

## Visual inspection

- Housekeeping and safety: no combustible materials in or around the plant, floor and surfaces clean, no physical damage, cylinders stored with caps and chains, fire detection and suppression working.
- Air path: ventilation and fans working, air intake filter mats, intake cover and ventilation filters in place, inlet air filter in good condition, compressor covers in place.
- Compressor: oil level at the manufacturer's mark and no oil leaks, where the compressor is oil-lubricated; drive belt undamaged, where fitted.
- Condensate: draining correctly at the compressor, the dryer, the in-line filters and the air tank; condensate containers emptied.
- Booster and backup: booster compressor without unusual noise or leaks; backup manifold holding pressure if it was not used in the past day; manifold pigtails in good condition.

## Readings to record

| Reading | What to compare it with |
|---|---|
| Plant room or container temperature | The manufacturer's operating range |
| Air compressor temperature | The manufacturer's range |
| Pressure dew point (refrigeration dryer) | Normally 3 to 5 °C; up to 6 °C is acceptable, higher calls for immediate inspection (Global Fund expected values) |
| Oxygen purity on the PLC and on a handheld analyser | 90 to 96%; above 90% is considered medical grade (Global Fund expected values) |
| Alarm codes | Identify the component and photograph the alarm |
| Running hours of the compressor, oxygen generator and booster | The preventive maintenance schedule, to see whether service is due |
| Booster stage pressures (temperatures once a week); cylinders filled and filling hours | The manufacturer's operating parameters |

Most of these values depend on the manufacturer, so the expected-values sheet asks operators to note their own plant's figures. Global Fund sustainability guidance also asks for oxygen purity to be recorded daily with at least two different analysers. A USAID operating procedure for PSA plants, written for hospitals in India, lists the same core daily items: pre-filter, oxygen purity, compressor pressure and oil level, tank pressures and dryer dew point.

On ULTRAOX SC plants, purity is measured by one or two zirconium oxide analysers, and the ULTRAOX touch screen shows purity, flow, pressure, the next maintenance due, a record of contingencies and alarm information. See also [what maintenance a PSA plant needs](https://library.ultracontrolo.com/answers/what-maintenance-does-a-psa-oxygen-plant-need/).

### What should the operator do if purity reads below 90%?

It is outside the expected range: WHO's interim PSA specifications (2020, superseded by WHO's technical specifications of 31 December 2024) called for an alarm below 90%, and the Global Fund expected values give 90 to 96%, with above 90% considered medical grade.

### Who should do the daily checks?

Operations or technical staff trained on the plant; Global Fund guidance recommends trained staff on site whenever the plant is running.

## Sources

- [Global Fund / Build Health International, PSA plant Daily Maintenance Checklist (2025)](https://resources.theglobalfund.org/media/xbanfgrc/cr_c19rm-psa-plant-daily-maintenance_checklist_en.pdf)
- [Global Fund / Build Health International, Daily checklist expected values (5 June 2025, French)](https://resources.theglobalfund.org/media/ge3bodrr/cr_c19rm-oxygen-plant-daily-maintenance-checklist-values_table_fr.pdf)
- [Global Fund / Build Health International, Overview: Sustainability Guidance for PSA Oxygen Plants (22 August 2024)](https://resources.theglobalfund.org/media/bwrp43cm/cr_c19rm-psa-oxygen-plant-sustainability_overview_en.pdf)
- [USAID RISE, SOP: PSA Plant Operations and Preventive Maintenance (March 2022), Annexure B](https://media.path.org/documents/SOP_on_PSA_Plant_USAID_RISE_04032022_F7fUBr6.pdf)
- [WHO, Technical specifications for PSA oxygen plants, interim guidance (8 June 2020)](https://www.who.int/publications/i/item/WHO-2019-nCoV-PSA_Specifications-2020.1)
- [ULTRAOX SC datasheet, p. 2; ULTRAOX datasheet 2022, p. 16](https://www.ultracontrolo.com/ultraox)
- [Ultra Controlo, Medical gas answers: What does an ULTRAOX plant monitor?](https://www.ultracontrolo.com/medical-gas-answers#what-does-an-ultraox-plant-monitor)
- [WHO, Technical specifications for health facility based medical oxygen systems (31 December 2024), note on the oxygen generator plant specification (supersedes the 2020 interim PSA specifications)](https://iris.who.int/server/api/core/bitstreams/ff437601-add3-44c8-8149-b85f0cdb2b52/content)

Reviewed: 2026-10-22. Ultra Controlo engineering. https://library.ultracontrolo.com/answers/what-daily-checks-does-a-psa-plant-operator-do/