Omega OMNI-AMPTM I, IIA, IIB User Manual

OMNI-AMP
Theromcouple Amplifiers
INSTRUCTION
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Unpacking Instructions

Remove the Packing List and verify that
you have received all equipment,
including the following (quantities in
parentheses):
OMNI-AMP Thermocouple Amplifier (1)
Operator's Manual (1)
If you have any questions about the ship-
ment, please call the OMEGA Customer
Service Department.
When you receive the shipment, inspect
the container and equipment for signs of
damage.
Note any evidence of rough handling in
transit. Immediately report any damage to
the shipping agent.
The carrier will not honor damage claims
unless all shipping material is saved for
inspection. After examining and removing
contents, save packing material and
carton in the event reshipment is
necessary.
The OMEGA ® OMNI-AMP thermocouple
amplifier is designed to boost small
thermocouple signals up to 100 times.
The OMNI-AMP amplifies the millivolt
signal generated by a thermocouple
(almost always less than 75 millivolts),
and drives meters or readouts that are
not sensitive enough to be driven directly
by the small output of the thermocouple.
There may be a temptation to use the
sensitive amplifier to drive a second
microvolt amplifier in order to achieve
even higher gains. However, the inherent
noise of the combined system will rule out
such use. OMNI-AMP Amplifier is ideally
suited for driving millivolt meters where
the full scale range is not more sensitive
than 100 millivolts without further
amplification. For example, when used
TM I, IIA, IIB
M0012/1100
NOTE
OMNI-AMP IIB Amplifier shown
with a meter having a full scale reading of
100 millivolts and OMNI-AMP Amplifier
set at the 100 gain position, the full scale
reading of the meter will represent 1.0
millivolt source voltage. This corresponds
to 77°F using a Type K, CHROMEGA
ALOMEGA ® thermocouple wire,
referenced at 320°F. See the OMEGA
Complete Temperature Measurement
Handbook and Encyclopedia
contains Temperature-EMF tables for
thermocouples.
Keep in mind, when working with
microvolt signals, that there is always a
possibility of picking up stray EMFs;
therefore, when using the high gain
positions, shielding and grounding of the
input and output leads is important. Be
sure to observe the proper thermocouple
input polarity. Note that the output range
of your OMNI-AMP Amplifier is - 1.5 to
+2.0 Vdc. Thermocouples are used in the
range of -450°F to +5000°F and the
output signals from them range from -10
millivolts to +80 millivolts. Thus, your
OMNI-AMP Amplifier is ideally ranged
and designed for them.
It is recommended to try using lower gain
settings first and use no greater gain
setting than is required. When a gain
setting of one (unity)is used, zero adjust
is inoperative. If a small offset EMF is
present, it is recommended that the zero
adjust on the readout device be used to
bring the instrument to zero. For
example; all panel meters have an
adjusting screw to set the pointer. When
using unity gain, it is only necessary to
turn this adjusting screw slightly to reset
the meter. Use the zero adjust on the
amplifier for all other gain settings.
Your OMNI-AMP Amplifier can drive both
high and low impedance devices. Most
meters and readout devices have high
impedance; i.e., over 1,000 ohms. With
® -
® which