The 3B18 is a wideband (20 kHz) single-channel signal conditioning module which interfaces, amplifies, and filters signals from balanced 4-arm full-bridge strain-gage bridges with a resistance from 100 Ω to 10 kΩ, providing simultaneous precision voltage and current outputs. The module provides two user-selectable (via front-panel switches) bridge excitation voltages: +10 V for bridges with a load impedance down to 300 Ω or +3.33 V for 120 Ω bridges or others below 300 Ω. Module bandwidth is also user-selectable between 20 kHz and 100 Hz, with user-supplied filter capacitors installed in the optional AC1310 ranging card. The 3B18 protects the computer side from damage due to field-side overvoltage faults up to 130 V rms. In addition, the current output withstands 130 V rms without damage and interfaces user equipment through screw terminals located on the 3B Series backplane. The 3B18 is a plug-in, mix-and-match, hot-swappable module which is easily field calibrated via front-panel zero and span adjustments for both voltage and current outputs.
3B Series Custom-Ranging Program
Externally-programmable Model 3B18-00, enables the user to configure a special input range by using the optional plug-on AC1310 ranging card, which houses user-supplied resistors to determine zero and span. To facilitate selecting resistors, a Windows® program, 3B-CUSTOM, calculates resistor values based on the user-desired input/output ranges.
Inside the 3B18 Series Module
A chopper-stabilized low-drift (±1µV/°C) input amplifier assures stable long-term stability. For user convenience, the zero and span can be factory configured to meet custom range needs (Model 3B18-CUSTOM) or can be externally programmed (Model 3B18-00) via user supplied resistors inserted in the optional AC1310 plug-on ranging card.