The Model FG220 Function Generator is designed especially for the biomedical and low level instrumentation field, offering features not found on any other generator in its price range. It provides constant amplitude sine, square, and triangle waveforms, with a frequency range of 0.01 Hz to 10 kHz. It features a calibrated and continuously variable output from 0 to 10 volts peak-to-peak, utilizing a vernier control and six switch-selected full scale ranges of 100 µV, 1 mV, 10 mV, 100 mV, 1.0 volts and 10 volts. Accuracy is ±2% of full scale on each range and has a constant output impedance of 100 ohms. The output mode switch allows selection of differential (balance) or common (single-ended) outputs.

The differential and common mode outputs provide a convenient way to measure the common mode rejection ratio of differential amplifiers. The CMRR is simply calculated by dividing the function generator's common mode amplitude setting by the differential mode amplitude setting which produces the same deflection as displayed on a monitor screen or the same voltage output as an amplifier being tested.

Housed in a lightweight, high-impact ABS plastic case, and being battery-powered, the Model FG220 Function Generator is ideal for bench or field use. Being battery-operated, it can eliminate possible ground loops and reduce AC interference, which can be so troublesome when working with low level signals. A blinking, power-on LED, located on the front panel, serves as a reminder to turn off the generator when not in use, thereby extending battery life. This same LED also functions as a low battery indicator. Output connectors are three 3-way binding posts on the front panel and three snap patient leadwire connectors on the back panel.

The Model FG220 Function Generator will provide the user with a fast and convenient way to test, calibrate and service a wide range of differential and common-mode input instruments such as monitors, oscilloscopes, recorders, amplifiers, etc. In addition, the low frequency and low amplitude waveforms can be used to calibrate and verify calibration of EEG/Polygraph instrumentation and power spectral analytic software/hardware.