Model 6120 is a two-channel, fully automated, high bandwidth, signal conditioning amplifier and filter with dual inputs. The bridge input has voltage and current excitation, automatic balance, shunt calibration and programmable configuration for 1/4, 1/2 and full bridge transducers. The AC-coupled auxiliary input is for ICP/IEPE, dynamic strain and other voltage output transducers.
The 6120 employs an amplifier-per-channel architecture which provides the highest accuracy and completely eliminates crosstalk between channels. Using Pacific's PI660 software zero and gain calibration and correction are automatic.
The bridge inputs have programmable constant voltage or constant current excitation, automatic balance and a shielded 8-wire input that supports remote sensing, shunt calibration and programmable bridge completion for 120 and 350 Ohm gages. Strain gages other than 120 or 350 Ohms are accommodated by changing a completion resistor. A two-wire auxiliary input for ICP type transducers has 1-20 mA constant current excitation with AC signal coupling.
Two-step local and remote shunt calibration is standard. Four-step remote shunt with plug-in resistor card is optional. Voltage substitution is provided for gain calibration with programmable attenuation, which makes the distribution of calibration signals less susceptible to contamination by noise and offsets. The programmable attenuator has steps of 1, 0.1 and 0.01 with 0.02% accuracy and a post-attenuator output is available for verification and calibration.
The differential instrumentation amplifier has programmable gains from 1 to 5,000 and automatic zero. Zero and gain calibration and correction are automatic using Pacific's PI660 software. Bandwidth is up to 100 kHz. The amplifier is followed by a low-pass filer that reduces alias errors in the sampled data. Each channel has a ±10 Volt calibrated analog output and a ±10 Volt monitor output.
The standard filter is a programmable four-frequency, eight-pole Bessel low-pass. A programmable, four-pole Bessel, low-pass filter with 1 Hz or 5 Hz frequency resolution is optional. Either the standard or optional filters may be obtained with Butterworth or other response characteristic.