Dataforth Introduces 8B43 Isolated Analog Signal Conditioners

Dataforth Corporation of Tucson, Arizona, has introduced the latest addition to its extensive line of miniature 8B isolated analog signal conditioners: the 8B43. This input module interfaces to DC linear voltage displacement transducers (LVDT) which operate on a 10V excitation voltage and up to 20mA of excitation current.

The 8B43 family includes 10 different modules with input ranges from -1V to +1V through -5V to +5V. Each module isolates, filters, and amplifies a voltage input signal, then provides an analog voltage output. Like all 8B modules, the 8B43 is an optimal solution for monitoring real-world process signals and providing high-level signals to a data acquisition system.

Specific 8B43 DC LVDT applications have included measuring soil sample deformation under load to determine soil strength, controlling pill weight and thickness in making tablets from medicinal powder, continuously monitoring fluid levels as part of a leak detection system (using a hydraulic oil compatible module) and replacing limit switches to ensure higher resolution on bottle inspection machinery.

Since Dataforth introduced the 8B signal conditioner in 2005, the line has expanded to 19 family groups and 123 different models. All 8B modules provide Instrument Class performance in a miniature 1.11” x 1.65” x 0.4” (28.1mm x 41.9mm x 10.2mm) housing. Their small size makes them ideal for embedded and portable applications.

Key 8B43 Features

• Interfaces to DC Linear Voltage Displacement Transducers
• Provides 10V Excitation with up to 20mA Current for DC LVDT Transducer
• ±0.05% Accuracy
• ±0.02% Linearity
• High-Level Voltage Outputs
• 1500Vrms Transformer Isolation
• Input Protection to 240VAC Continuous
• ANSI/IEEE C37.90.1 Transient Protection
• 100dB CMR
• 1kHz Signal Bandwidth
• Low Drift with Ambient Temperature
• CE Compliant
• UL/CUL Listing and ATEX Compliance Pending
• Mix and Match Module Types on Backpanel

Signal filtering in the 8B43 is achieved with a 5-pole filter that is optimized for time and frequency response and provides 100dB per decade of normal-mode rejection above 1kHz. One pole of the filter is on the field side of the isolation barrier for anti-aliasing; the other four are on the system side.

A special input circuit provides protection against accidental connection of power-line voltages up to 240VAC, while clamp circuits on the I/O and power terminals protect against harmful transients. Isolation is provided by transformer coupling to suppress transmission of common mode spikes or surges. The module is powered from +5VDC, ±5%.

Designed for installation in Class I, Division 2, hazardous locations, the 8B43 offers a high level of immunity to environmental noise.