Wall mounting oxygen measurement for % levels


wall mounting
temperature controlled
safe area operation

Download a datasheetRequest a quoteCall us


Oxygen measurement in a safe area.

The PMA20 provides fast, accurate and reliable oxygen measurement in a compact wall mounting system.

Paramagnetism is significantly higher for oxygen than other common gases.  The M&C magneto-dynamic measurement cell uses this physical phenomenon to provide the most accurate and reliable measurements available.

The small (2 ml) flow cell houses a robust sensor that can have a flow rate of up to 1 l/min. The small cell design improves speed of response and the paramagnetic sensor measures oxygen concentrations with a response time of less than 3 seconds.

The analyser is able to have 5 selectable ranges:

  • 0 to 1%
  • 0 to 3%
  • 0 to 10%
  • 0 to 30%
  • and 0 to 100%

This allows this system to be used for trace level oxygen measurements as well as oxygen purity applications.






Measuring range

Selectable for 0 to 3, 0 to 10, 0 to 30, and 0 to 100 vol% O2, linear.

Response time for 90 % FSD

< 3 seconds at 60 Nl/hr air

Accuracy after calibration

Deviation: analogue = ±1 % of span /

digital = ±0.1 vol.% O2


Deviation: analogue = <1 % of span /

digital = ±0.1 vol.% O2

Influence of ambient temperature

No influence up to 45 °C

Influence of barometric pressure

The oxygen reading varies in direct proportion to changes of the barometric pressure

Influence of sample gas flow

Variation of gas flow between 0 to 60 Nl/hr air will cause a difference of < 0.1 vol.% O2

Sample gas inlet pressure

0.01 up to 1 bar g, (PMA20 required admission pressure for competent flow rate, no pump inside)

Sample gas outlet pressure

Outlet of analyser must discharge freely into atmosphere

Flow rate of sample gas

Max. 60 Nl/hr air, adjustable with needle valve on the flowmeter 7 to 70 Nl/hr

Temperature of sample gas

-10 to +40 °C, dry gas

O2 transducer temperature

Fixed at +50 °C

Ambient temperature

-10 to +45 °C

Storage temperature

-20 to +60 °C, relative humidity 0 to 90 %rh



CE marked

IP protection

IP 53 EN 60529

Electrical standard

EN 61010


Shipping weight

3 Kg



220 H x 214 W x 182 L mm


Plastic wall mounting housing, grey/blue

Wetted materials

Platinum, Glass, Polypropylene, 316 (TI) Stainless Steel, FPM, Epoxy resin



Internal power unit 230 VAC standard, 115 VAC available ±10 %, 40 to 60 Hz, 26/5 VA


Terminals 2.5 mm2, 1x PG11, 1x PG13.5 cable gland

Sample gas connection

PP hose connectors DN 4/6 for 4 mm i.d. and 6 mm o.d. tube


Output signal

0 to 1 VDC, non-isolated, load > 100 KΩ, for the range of 100 Vol%, and 0 to 20 mA or 4 to 20 mA for the chosen range, non-isolated, max. load 300 Ω

Analogue indication

Selectable for each range with a scale of 0 to 30 and 0 to 100%

Digital indication

3 ½ digit 18 mm high LCD for 0 to 100 % O2 reading, selectivity 0.1 vol.% O2

Analogue/Digital indication

Analogue: selectable for each range with a scale of 0 to 30 and 0 to 100%. Digital: 3 ½ digit 9 mm high LCD for 0 to 100 % O2 reading, selectivity 0.1 vol.% O2.

All specifications subject to change