2312G INSTRUCTION MANUAL
56-101-00550-D CH.
1
11/7/14
Page 5 / 20
CHAPTER 1: PRODUCT DESCRIPTION
1. GENERAL DESCRIPTION
A. The 2312G provides the means for quickly test, calibrate and troubleshoot a turbine
temperature indicating system installed on this type of engines. It has sufficient sensitivity
and accuracy to test thermocouple and system resistance, insulation, and indicator
calibration. It features portability, simplicity of operation, direct reading, and multifunction
versatility.
B. The 2312G is supplied with a vinyl carrying case with test cable compartment and a plug-in
test cable (except 2312G-8, P/N 101-00557).
2. THEORY
A. The low resistance ohmmeter circuits are the four-wire type. This circuit virtually eliminates
the effects of lead wire resistance so that direct readings as low as 0.02 ohm are easily
done.
B. A high resistance ohmmeter measures resistance leakage up to one (1) megaohm. The
45-volt power supply often reveals leakage that is not detected by conventional low voltage
ohmmeters, but is well within circuit insulation limitations.
C. A Wheatstone Bridge circuit provides an accurate direct reading of lead resistance. A self-
contained resistance standard is provided for calibration immediately before making lead
resistance measurement. This eliminates the need for measuring test lead resistance and
subtracting its value from subsequent measurements. A unique transistor switching circuit
protects the meter from overloads due to attempting measurements much lower or higher
than nominal.
D. For indicator calibration tests, an adjustable thermocouple simulator is provided with
simulated lead resistance. Ambient temperature correction is set by a panel adjustment and
direct comparison made between the 2312G and the indicator under test up to 1000
C.
3. SWITCHING FUNCTIONS
(Refer to Figure 4.)
A. The meter bezel knob (3) permits setting of the meter pointer as required.
B. The “CAL. ADJUST” control knob (4) permits exact adjustment to desired test points when
used in conjunction with the “TEST” pushbutton (6) or the “CAL” pushbutton (7).
