Air Receiver Pressure: The Leak Shows as Start Count Air receiver pressure falls slowly and nobody looks. The side effect is the signal: the compressor starts more often. Where to measure and where our range stops.

The signal is not the gauge, it is the start count

An air receiver sits in a corner with a gauge on it. Nobody reads the gauge unless something has already failed. But a receiver with a slow leak has a side effect that people do hear: the compressor starts more often. By the time that becomes annoying — or shows up on the electricity bill — the leak has usually been there for weeks.

That is why receiver monitoring is worth doing even where nobody wants another dashboard: the measurement answers a question maintenance is already asking.

Reading the numbers

• Overnight loss from 8 to 5 bar — a steady leak. Fittings, quick couplers, a condensate

drain that does not seat, a hose that has been rubbing.

• Very slow loss (0.3 bar per night) — may be condensation and temperature, not a leak.

Record several nights before acting.

• Fast loss under load — this is usually capacity, not leakage: a saturated filter,

worn belts, a restricted intake.

Where to measure

The measurement point matters more than the sensor:

• After the receiver, after the dryer and filters is where you see the pressure the

equipment actually receives. That is the number worth protecting.

• At the compressor outlet you see production, not the loss in the line.
• If the working pressure is above our range, **put a regulator before the measurement

point** and measure downstream of it.

Range, said first

Our standard sensor is 0-500 kPa gauge (about 5 bar), ±2 kPa, IP67, on a replaceable CR1632 cell that lasts about 1.5 years without re-pairing. It is read on a phone: no receiver, no wiring, no display to mount.

A typical workshop receiver runs at 7-10 bar, which is above that range. Two honest options: a different sensor, or the regulator arrangement above. We say which one applies before quoting.

What it does not do

It is not a pressure-vessel certification and it does not replace the safety valve — those are code requirements, not monitoring. And without a receiver there is no continuous alarm: this is a "look once a shift or once a day" instrument, plus a record that the look happened.

Used that way, it turns a leak from something discovered at failure into something found in days — which on a compressed-air system is where most of the money actually goes.