5 PRE-OPERATIONAL
CHECK
5.1 Unpacking
Remove the instrument from its packing case and remove any shipping ties, clamps, or packing materials. Carefully
follow any instruction given on any attached tag. Inspect the instrument from scratches, dents, damages to case corners
etc. which may have occurred during shipment.
If any mechanical damage is noted, report the damage to the shipping carrier and then notify
OMEGA
directly or its
nearest agent, and retain the damaged packaging for inspection.
A label, on the back of the instrument case, indicates the serial number of the instrument. Refer to this number for any
inquiry for service, spare parts supply or application and technical support requirements.
OMEGA
keeps an updated data
base with all information regarding your instrument.
5.2
Preparation for the start-up
Remove the calibrator from the carrying case and place it on a flat surface.
Connect the instrument to a mains supply with the nominal voltage specified on the back label (115 or 230 Vac).
Remember that the instrument requires a power of approximately 800 VA. For safe operations the equipment must be
correctly connected to ground.
5.3 Wiring
practice
Although most temperature indicators are designed to be insensitive to transient or noise, the following recommendations
should be followed to reduce pick up in the signal leads and to ensure good general performances. The signal leads
should not be run near ac line wiring, transformer and heating elements. Connection leads should, if possible, be twisted
and shielded with the shield grounded at the end of the cable. When shielded cables are used the shield must be
connected to the positive terminal. Appropriate extension wires should be used for thermocouples unless the
thermocouple leads permit direct connection.
Make sure that both the thermocouple and the compensating cable are connected with the correct polarity. If in doubt,
the polarity of the compensating leads can be checked by connecting a length of lead to the indicator, shortening the
free ends of the wires together and noting that the indicator reading increases when the wires connection is heated.
Color codes of compensating cables change in different countries. Check the appropriate table (A).
For Resistance Temperature Detector connection use a cable of adequate gauge to lower the overall input resistance.
The use of a cable with a good resistance balance between conductors is also necessary.
Table A
Colour code & polarity for extension wires (ANSI)
Thermocouple
Wires
Colour
code
E
Chromel
( + )
Chromel
Purple
Constantan
( - )
Constantan
Red
J
Iron
( + )
Iron
White
Constantan
( - )
Constantan
Red
K
Chromel
( + )
Chromel
Yellow
Alumel
( - )
Alumel
Red
R
Pt 13% Rh
( + )
Copper
Black
Platinum
( - )
Alloy 11
Red
S
Pt 10% Rh
( + )
Copper
Black
Platinum
( - )
Alloy 11
Red
T
Copper
( + )
Copper
Blue
Constantan
( - )
Constantan
Red
B
Pt 6% Rh
( + )
Copper
Pt 30% Rh
( - )
Copper
N
Nicrosil
( + )
Nicrosil
Orange
Nisil
( - )
Nisil
Red
10
