Reference Air Inlet (Probe); Inline Shut-Off Valves; Internal Test Gas And Reference Air Tubes (Autocal Unit) - ABB Endura AZ25 Series User Manual

Endura AZ25 series probe
Combustion oxygen monitor

4.4.6 Reference air inlet (probe)

A clean, dry, continuous instrument air supply, free from
hydrocarbons is required, (supplied for example, from an ABB
pump or filter-regulator – see Appendix B, page 33.
Connect the reference air tubing to the external reference air
inlet at the probe – see Fig. 4.8, page 27.
Note.

The reference air supply must be to instrument air
standards – clean, dry and free of oil vapor and
particle contamination; see schematics in Section 3.5,
page 9.

ABB recommend using the ABB 5µm / Oil Coalescing
Filter Regulator to supply reference air – Appendix B,
page 33.

If oil vapor is suspected, use an ABB Reference Air
Pump to supply reference air to the probe – Appendix
B, page 33.
Endura AZ25 probe
External reference air inlet –
0.3 to 0.5 l/min (0.64 to 1.06 scfh) flow required
Fig. 4.9 Reference air inlet at probe
28

4.4.7 Inline shut-off valves

On non-AutoCal systems, if the test gas line is connected
permanently and is >10 m (33 ft.) from the supply, fit non-return
valves at the probe head to prevent breathing of flue gas in and
out of test gas lines– refer to Section 3.5, page 9 for schematics
of all configuration options.

4.4.8 Internal test gas and reference air tubes (AutoCal unit)

Endura AZ25 AutoCal unit
Test
gas 2
Fig. 4.10 Internal test gas and reference air tubes – AutoCal unit
4 Electrical connections
Reference
air tube
Test
gas 1
OI/AZ25P–EN Rev. E