UFI Model 1089 Family of Checktrodes™

Physiological recordings can be easily contaminated by noise and interference. In many cases, high electrode contact impedance is a big part of the problem. Noise often appears as 50 or 60 Hz "hum" from surrounding AC-powered electrical devices or as erratic spikes due to any motion of the lead wires. In virtually every case, these troublesome artifacts can be mitigated or completely eliminated by reducing contact impedance at the skin/electrode interface. UFI's Checktrode™ applied electrode contact impedance testers are designed to help accomplish this task.

UFI offers four time-saving and frustration-saving electrode contact impedance checking instruments. Our standard 1089 allows rapid evaluation of contact impedance when two electrodes are used. For multiple electrode configurations, our 1089ES and 1089NP allow rapid, individual evaluation of large electrode arrays such as EEG caps. The 1089e is our latest offering -- and at an economical price too!

Model 1089 MkIII Checktrode

The UFI model 1089 MkIII Checktrode supplies quick and easy evaluation of total contact impedance and offset voltage between two applied electrodes. The 1089 uses an AC excitation method which removes the effects of the polarization errors from the impedance reading. Leads with both the older .080" pin plugs as well as the newer .060" sheathed safety jacks are supported. The inclusion of a standard male snap allows electrode lead testing as well. A loaded battery test function is also provided. The 1089 is powered by a standard 9V battery, and automatically shuts down after 5 minutes.

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Model 1089ES Checktrode with Lead Selector

The "ES" includes a switch and associated circuitry to select up to 22 separate electrode leads. The ES essentially checks each selected electrode against all of the other electrodes connected together. This allows the 1089ES to be used to check applied electrode contact impedance of many multiple electrode configurations including Cranial EEG "caps", rapidly and painlessly. Price includes interfacing to the connector of your choice for most connectors. Contact UFI for more details.

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Model 1089NP Checktrode with Lead Selector

The Model 1089NP evolved from the 1089ES, and has a few important differences. Whereas the 1089ES is a general-purpose instrument, the Model 1089NP is intended for use with several specific electrode caps. These include the Brainmaster Discovery qEEG system cap, the NeuroPulse Systems qEEG cap, the Mistar Systems cap and any standard Electro Cap or Comby Cap used with other qEEG systems. All these caps assume the use of a 'linked ear reference' system, so the linked ear electrodes are the reference against which all of the other electrodes are individually checked.

For ease of use, Model 1089NP rotary selection switch positions are directly keyed to electrode site names for the listed caps. A two-position TEST switch permits the two reference electrodes supplied with these caps to be tested against each other. When good contact between them has been established, just flip the TEST switch to link the two reference electrodes, then check contact impedances of the remaining cap electrodes.

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1089 general specifications

Model 1089e Economy Checktrode

Built on years of 1089 Checktrode service, this new design incorporates a microprocessor. A crystal-controlled 30 Hz sine wave is supplied to the electrode pair under test. Leads connect to the electrodes using the industry standard 0.060" safety jacks. The 1089e supplies a simple pass-fail LED indication for the contact impedance ranges of <5KOhm, <10 KOhm, <20 KOhm, <50 KOhm, and >50 KOhm. Simple, single-switch operation, with automatic power-down, further simplifies the use of this essential, 9V battery-powered instrument.

Model 1089e specifications

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Published references to the Checktrode

Product Families:
Bioamps/signal conditioners
Ambulatory data loggers
Hot Flash Recording
BAERCOM™ hearing tester
PC-based instruments
Multi-subject systems
Test instruments