24
Original instructions
14.8
Air filtration
FORTiS-S FS system encoders can be operated with an additional compressed air supply to increase
the level of ingress protection from IP53 to IP64. If using air purge the air supply must meet pressure and
cleanliness criteria as shown in the table below at the supply input of the encoder.
It may be convenient to connect the air purge supply to the system part that will be fixed, i.e. depending
on the machine configuration and axis movement, either the extrusion or the readhead may move with the
machine slideway.
Air inlets are included on both sides of the readhead and on both the extrusion end caps. Use a suitable
air supply hose with a 4 mm bore.
WARNING:
Remove the blanking plug only from the position at which the purge air supply is to be
connected, or the sealing integrity may be compromised.
Air supply cleanliness requirements
Air supply pressure
1 bar (pressure at encoder air inlet; air inlet connector has an
integrated throttle that ensures the correct volume of airflow of
2 l/min through the encoder)
Air quality
Particle size
0.1 μm to 0.5 μm
0.5 μm to 1.0 μm
1.0 μm to 5.0 μm
No. of particles per m
3
≤ 20 000
≤ 400
≤ 10
Max pressure dew point
ISO 8573‑1 Class 4 (pressure dew point at 3 °C)
Total oil content
ISO 8573-1 Class 1 (max. oil concentration: 0.01 mg/m
3
)
Removal of the air supply bung and fitment of the air connection fitting into either the readhead (1)
or extrusion end cap (2). Finger tighten (0.3 Nm maximum).
1
2