The S2A and SC-200 LVDT signal conditioners are very similar; however, each unit was designed with specific features for the markets it serves in mind, so there are a few differences between them.
The S2A was specifically designed for the power generation industry and has the following features:
1) LVDT excitation frequencies of 1, 3, 5, and 10kHz. The 1kHz and 3kHz frequencies were selected so the conditioner could be used with GE and Westinghouse steam turbine LVDTs and LVRTs.
2) If the S2A senses a sensor-related fault, the module's fault-response outputs are activated and in addition, the analog output is driven out of range. This is done so that in a redundant sensor configuration, by using an algorithm coded into the turbine's DCS control system, the faulty reading is identifiable and is not be accepted by the DCS with the other correct sensor readings.
3) The I/O screw-terminal plugs are color-coded and are removable for easy installation.
Figure 1 S2A
The SC-200 was designed for standard industrial applications and has the following features:
1) LVDT excitation frequencies of 2.5, 5, 7.5, and 10kHz. The 2.5kHz frequency is commonly used by LVDT manufacturers and the 7.5kHz frequency was selected to be used with Marposs analog pencil gaging probes. Alliance Sensors Group is an official distributor for Marposs USA.
2) The analog output is NOT driven out of range should the SC-200 sense a fault, but the module's other fault-response outputs are activated.
3) The I/O screw-terminal blocks are not removable.
Figure 2 SC-200
S2A
Product Link: https://www.hgsind.com/product/s2a-lvdt-signal-conditioner
Video Link: https://www.hgsind.com/videos/s2a-lvdt-signal-conditioner-product-overview
Manual Link: https://www.hgsind.com/sites/default/files/2019-05/5700-0014%2C%20Rev%20P%2C%20S2A%20manual_0.pdf
SC-200
Product Link: https://www.hgsind.com/product/sc-200-lvdt-signal-conditioner
Video Link: https://www.hgsind.com/videos/sc-200-lvdt-signal-conditioner-product-overview
Manual Link: