The 1089NP provides the ability to test the reference electrodes against each other (using the toggle switch on the upper right corner) in order to verify the reference first, then changing the toggle switch shorts the reference electrodes together (linked ear configuration) and then individually tests each electrode position against the linked ear reference.
The 1089NP impedance meter is specific to EEG systems, which has electrode site labels (FP1, FP2, ...) for each switch position insteade 1089NP works with NeuroPulse qEEG Systems, Brainmaster Discovery qEEG systems, Mistar Systems or any qEEG system using a standard Electro Cap or Comby Cap.
The "NP" includes a switch and associated circuitry to select and rapidly check electrode contact impedance of up to 22 separate electrode leads.
Impedance display: 3 1/2 digit LCD display
Contact impedance range: 0-199 KOhm (custom ranges available
Excitation frequency: 30 Hz.
Typical excitation current: 10 uA p-p (constant current)
Calibration setting: 50 KOhms
Input connectors: 2 ea. .080" and .060" safety jacks and 1 male snap