Many observable physiological and biological changes produce a change in impedance which can be easily measured with this compact instrument. High frequency excitation minimizes artifacts from offset voltages present. Built-in balance pot and meter make initial setup a snap.
Internal circuitry separates and supplies both a D.C. and an A.C. (long or short time constant) output. Front panel calibration switch (0.25 Ohms) allows rapid checkout of 2991 operation and recording equipment function. Battery powered (9V) for field use.
- High Gain Impedance to Voltage Front-end
- Excitation Frequency: 75 KHz.
- Input Connector: 5 way Binding Post
- Impedance Range: 1 to 2000 Ohms
- Front-end Offset Correction: 10 Turn Balance control
- Front-end Balance Indicator: Analog MeterOutputs Supplied: D.C. and A.C. (BNC)
- Output Level for 0.25% change in Z: DC -- 250 mV, AC -- 2.0V (approximate)
- Output Impedance: 4 KOhms (typical)
- Noise Level: less than 5 mV p-p
- Power: 9V Battery (with built-in Test capability)
- Compact Plastic Case: 7" x 5" x 2.5"
- Weight: 1.0 lb.
- Optional Equipment: EKG Filter (2991 EF only)
- Provides Respiration and unamplified EKG from the same two electrodes