DESCRIPTION
The Ectron Model 451 is a unique advance in conditioners for LVDT* and RVDT* transducers. For the first time, the conditioner can be calibrated to the transducer without using a costly and time-consuming laboratory procedure. And autozero can be commanded at any time. Plus, the Model 451’s display indicates the analog output voltage and actual transducer displacement in real time!
The Model 451 excites the transducer according to user set parameters for voltage and frequency. A variable gain differential amplifier receives the resulting signal which is then coupled to a synchronous detector, user controlled four-step filter, analog-to-digital converter, and micro-controller. Here, all functions from arithmetic calculations, to front-panel data and menu displays, to user interface operations are controlled. In parallel, the displacement data is calculated and coupled to the front panel for display. Finally, a digital-to-analog converter and output analog stages produce the desired analog output signal. The display indicates both the analog voltage and the actual transducer displacement. Settings, maintained in nonvolatile memory, are entered into the Model 451 using the front panel controls.
OPERATING MODES
Example Mode
Mount the LVDT; then position the apparatus under test to one position of its motion (usually one extreme) and command the Model 451 to “capture” Point 1. Repeat with a second position to “capture” Point 2. Then key in the desired output voltages corresponding to the two points and you’re through! For exact indication of displacement, the sensitivity constant** for the transducer must be entered.
Scale Mode
For the LVDT in use, key in two points of the expected motion in units of displacement and the corresponding desired output voltages, plus the sensitivity constant** of the transducer. That’s it.
Gain Mode
Key in the desired conditioner gain. The analog output voltage will equal the input voltage (from the transducer) times this gain. This is the conventional operating mode of existing LVDT conditioners. The Model 451 front panel will display distance if the sensitivity constant** of the transducer has been entered as well as the corresponding output voltage. If desired, an autozero can be commanded at any time.
* LVDT—Linear Variable Differential Transformer
* RVDT—Rotary Variable Differential Transformer
** The sensitivity constant of an LVDT, usually supplied by the manufacturer, is a factor linking excitation voltage and output voltage change to displacement. It is normally expressed in mV output per volt of excitation voltage per mil of displacement. For RVDT’s, the displacement is normally in degrees. This constant can be accurately measured using the Model 451.
400 SERIES ENCLOSURES
Ectron 400 Series enclosures provide connector interface for power and signal input and output connections for 400 Series products. Portable, bench mount, rack mount, and signal-conditioning systems are available with capacities from 6 to 22 conditioners. The following Ectron products are interchangeable in these enclosures: the Models 352 and 428 conditioner amplifiers, the Model 441A/AL frequency-to-voltage converter, and the Model 451 LVDT/RVDT signal conditioner. Thermocouple conditioning can be added using the 200 Series T/C Mate.
FEATURES
- Calibrated Performance Without CAL Lab Testing
- Front-Panel Display of Voltage and Actual
- Displacement in mils, mm, or degrees
- Precision Digital Processor Design
- Calibration of Transducer and Conditioner While Installed
- Autozero on Command
- Three Modes of Operation: Example, Scale, and Gain
- LVDT* and RVDT* Operation
- Operates as a Carrier Amplifier for Bridge Transducers
- Designed for Poor Environments
- Measurement of an LVDT’s or RVDT’s Sensitivity Constant
