EMSIS – User’s and Installation Manual
and unterminated solid lines on the other. Red line connects to the 12 V DC avionics power bus and blue
line connects to the aircraft common ground. If you find power cable too long, you can shorten it to any
length, saving some precious weight.
When you use more than one EMSIS unit in the cockpit, other EMSIS units get power via CAN cable.
In Appendix at the back of this document you will find connection schema for EMSIS unit with or without
UPSU unit.
7.3 Pitot-Static Connection
In most avionics installations there are several instruments that need to be connected to the pitot-static
system. A typical instrument panel has at least a mechanical airspeed indicator and altimeter. EMSIS PFD
unit shares the same pitot-static source with them.
Pitot-static consists of static pressure tubing and total pressure tubing.
In order to connect to the static source, cut the static tube on an appropriate place and insert plastic T
junction. Cut some new tube to length and connect T junction with the EMSIS PFD static port. We
recommend use of hose clamps on all junctions and connections to secure against slippage and to reduce
chance of static pressure leak.
Use the procedure above for the total pressure tube as well: cut the total pressure tube, insert T junction,
connect T junction and EMSIS total port and secure connections using hose clamps.
We strongly recommend labelling each tube before connecting to the EMSIS PFD or any other instrument.
If you ever have to remove EMSIS PFD from the instrument panel, this will help a lot when you will
reinstall it.
7.4 Outside Air Temperature Probe Installation
Although the OAT probe is a simple element in the EMSIS PFD system, its installation requires some
attention.
Outside air temperature (OAT) probe is shipped with the EMSIS PFD unit. This is a digital temperature
sensor inserted into a threaded aluminium tube. The default OAT cable length is 1.5 meters but other
lengths are available on request.
OAT information is required to calculate true airspeed from indicated airspeed and altitude, as well as to
provide you with the outside temperature information.
In order to provide accurate measurements, the OAT probe must be installed on a proper place where the
probe is not exposed to the disturbing sources of heat:
engine heat and exhaust heat,
direct sunlight,
heated air exited from cabin.
We also do not recommend installing the probe in the cabin area, since the elevated temperature in the
cabin may influence the back side of the probe, though such influence is usually small.
Please follow these steps to install the OAT probe:
1. Locate a spot in the aircraft taking into account the considerations from above and drill a
ϕ
8 mm
hole.
2. Remove the external nut from the probe but keep the washer, internal nut and plastic insulation
tube on the probe.
3. Install the probe into the hole
from the interior
. Guide the cable trough the aircraft to the EMSIS
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