High Temperature Dual Transducer Case Expansion Transducer with Weatherproof

Product Specification

Thermal Case Growth Measurements in Large 
Turbines
 An important position measurement in Turbine Supervisory 
Instrumentation (TSI) is case expansion. Case expansion 
(sometimes referred to as shell expansion) is the thermal 
growth of the machine case as it expands during machine 
startup and on-line operations.  The case expansion 
transducer system is typically mounted on the foundation at 
the opposite end from where the turbine casing is attached 
to the foundation and provides information about the growth 
of the machine case relative to the foundation.
 Case expansion is a parameter that you should use a dual 
transducer arrangement to measure.  This arrangement 
provides information about the position of the sliding feet on 
the machine case.  A condition that obstructs or jams one 
foot could distort the case and damage the machine.  The 
dual case expansion transducer configuration in conjunction 
with the 3300 or 3500 monitors provides an alarm for this 
condition.  The high temperature dual case expansion 
transducer configuration is compatible only with the 3500/45 
Position Monitor.
 Case expansion measurements also enable you to 
determine whether machine conditions are exceeding 
expected temperature growth differentials.  This is primarily a 
startup parameter that determines whether the machine 
casing and rotor grow thermally at nearly the same rate.  
Different rates of thermal growth can cause the rotating and 
stationary parts of the machine to rub.
 The case expansion transducer assembly consists of a linear 
variable differential transformer (LVDT), which is housed in a 
weatherproof, protective enclosure.

Specifications
 24765 dc LVDT Assembly 
Electrical
 Input Power +24 Vdc, 30 mA minimum
 Scale Factor
 24765-01 0.346 V/mm (8.79 V/in).
 24765-02 0.404 V/mm (10.25 V/in).
 24765-03 0.143 V/mm (3.63 V/in).
 Linear Range
 24765-01 ± 12.7 mm (±0.5 in).
 24765-02 ± 25.4 mm (±1.00 in).
 24765-03 ± 51 mm (±2.00 in).-3 dB Frequency
 24765-01 20 Hz
 24765-02 15 Hz
 24765-03 10 Hz
 Output 
Impedance
 7 kΩ. nominal, all models
 Minimum Load Resistance
 24765-01 50 kΩ
 24765-02 100 kΩ
 24765-03 200 kΩ

135613 dc LVDT 
High Temperature Case Expansion 
Transducer System 
Electrical
 Input Power +13.5 to +26  Vdc 
unregulated, 30 mA 
minimum
 Voltage                                              +1 to +6 Vdc, all models 
Output Noise <10 mV 

Scale Factor
 135613-01 and -11 0.20 V/mm (5.0 V/in)
 135613-02 and -12 0.10 V/mm (2.5 V/in)
 135613-03 and -13 0.049 V/mm (1.25 V/in)
 Linear Range
 135613-01 and -11 25.4 mm (1.00 in)
 135613-02 and -12 50.8 mm (2.00 in)
 135613-03 and -13 101.6 mm (4.00 in)-3 dB Frequency
 135613-01 and -11 200 Hz (typical)
 135613-02 and -12 200 Hz (typical)
 135613-03 and -13 200 Hz (typical)
 Stability 0.125% full-scale
 Non-Linearity Less than 0.25% full-scale
 Temperature 
Coefficient
 0.05%/°C (0.028%/°F) 
maximum

Dimensions 
Body Length  
135613-01 and -11 171 mm (6.75 in)
 135613-02 and -12 209 mm (8.24 in)
 135613-03 and -13 297.4 mm (11.71 in)
 Body Diameter 19.2 mm (0.75 in), all 
models
 Body End to Null Center
 135613-01 and -11 65.4 mm (2.57 in)
 135613-02 and -12 84.3 mm (3.32 in)
 135613-03 and -13 129 mm (5.07 in)
 Core Length 
135613-01 and -11 87.6 mm (3.45 in)
 135613-02 and -12 87.6 mm (3.45 in)
 135613-03 and -13 135 mm (5.30 in)
 Core Diameter 4.8 mm (0.19 in), all models