A-MSystems 1800 Instruction Manual Download

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A-M Systems

131 Business Park Loop, P.O. Box 850 Carlsborg, Wa 98324
Telophone: 800-426-1306 * 360-683-8300 * FAX: 360-683-3525
E-mail: [email protected] * Website: http://www.a-msystems.com

ROCEDURE

Controls

Inputs / Observations

Adjust / Check

Observe voltage on pin 4

Check for -15 V

of the op-amp

Observe voltage on pin 7

Check for +15 V

of the op-amp

ROCEEDURE

Controls

Inputs / Observations

Adjust / Check

POWER: OFF

Remove op-amp

POWER: ON

Observe voltage on pin 4

Check for -15 V

of the op-amp socket

Observe voltage on pin 7

Check for +15 V

of the op-amp socket

POWER: OFF

Replace op-amp or
remove an additional
op-amp for further testing

POWER: ON

Zeroing

The following procedure calibrates Channel 1.

Controls

Inputs / Observations

Adjust / Check

POWER: ON

Connect

PROBE+

and

PROBE-

Adjust T100 for 0.0 V

to instrument

GND

Observe voltage at TP101

Observe voltage at TP102

Adjust T101 for 0.0 V

Observe voltage at TP103

Adjust T103 for 0.0 V

Repeat this proceedure for locations TP201 through TP203 and T200 through
T203 to calibrate Channel 2.

Summary of Contents for 1800

Page 1: ......

Page 2: ...FOR MICROELECTRODE AC AMPLIFIER MODEL 1800 Serial __________ Date____________ A M Systems Inc PO Box 850 Carlsborg WA 98324 U S A 360 683 8300 800 426 1306 FAX 360 683 3525 http www a msystems com Version 7 0 Febrary 2002 ...

Page 3: ... Features 1 Controls and Connectors 2 Operating Instructions 4 Typical Set Up Procedure 4 Problem Solving 6 Theory of Operation 9 Overview 9 Operational Modes 10 Component Modules 12 Calibration Proceedures 13 Specifications 18 Warranty and Service 19 Each Microelectrode Amplifier is delivered complete with Two Head Stage with 5 Foot Cables Six 4 Inch Electrode Connector Cables Rack Mount Hardware...

Page 4: ...g extracellular neurophysiological recording from excitable tissue such as nerve muscle EMG EEG EKG and ERG recordings The instrument is not intended for clinical measurements using humans Each channel of the Model 1800 contains a high gain low noise differential amplifier stage followed by low frequency high frequency and notch filters Three operating modes are available to accomodate recording s...

Page 5: ...BE GND connector is tied to the indifferent lead If you desire to have the current constrained to a known path you may want to place the GND elsewhere Actual GND placement depends on the application MODE This rotary switch controls the operating mode for its channel The switch allows the user to select Record Mode REC Stimulate Mode STIM or Impedance Check Mode IMP GAIN This rotary switch controls...

Page 6: ...ill be attenuated by a factor of 100 while a 1 Hz signal will be attenuated by a factor of 10 000 The Low Cut Off frequency should be selected based on the frequency content of the signal to be recorded One of the uses of this filter is to reduce slow variations or DC levels in the input signal HIGH CUT OFF This rotary switch enables the user to select the upper boundary frequency at which point t...

Page 7: ...l to be recorded The GAIN Switch should be set so that the signal at the OUTPUT connector is less than 10 V otherwise higher and or lower portions of the signal may appear cut off or flattened Stimulating The MODE switch should be placed in the STIM position Stimulation current I is monitored by measuring the voltage V across an internal fixed resistor R 1 k in series with the electrodes Since I V...

Page 8: ...y time during an experiment the impedance of one or both electrodes can be checked by selecting IMP with the MODE switch In this mode an internal oscillator automatically passes a 0 1 µA 1 kHz sine wave current I through the electrode and the probe amplifier monitors the resultant voltage V that develops across the electrode Since R V I and I is known the monitored voltage is a measure of the elec...

Page 9: ...g the voltage developed across a 1 k resistor in series with the electrode In Impedance Mode an internally calibrated current is passed through the Probe to one electrode and the Probe monitors electrode impedance by measuring the voltage that develops across the two electrodes The signal from the Probe passes through the differential amplifier which has a unity gain in Record and Stimulus Modes a...

Page 10: ...ferent electrode lead At the same time relay R2 turns on and RL14 turns off Relay RL11 connects the stimulus source at the STIMULUS connector to the electrode leads A stimulus current from an isolated source passes through the PROBE lead to the active electrode returning through the PROBE lead and the 1 k resistor The current creates a voltage across the resistor which is amplified by the Probe am...

Page 11: ...source A400 andA401 which converts the sine wave voltage to a sine wave current of 0 1 µAp p at 1 kHz The calibrated current source is connected to relay RL11 which switches the current to the electrode leads The Capacity Compensation feedback circuit A402 reduces the amount of capacitance across the electrodes allowing only the resistive component of the electrode to be measured Component Modules...

Page 12: ...that all input cables are shielded The following procedures assume that the Model 1800 has been properly adjusted and calibrated Initial Settings Controls Inputs Observations Adjust Check LOW CUT OFF 10 HZ HIGHCUT OFF 10KHZ Record Mode Controls Inputs Observations Adjust Check MODE REC Apply a 1 mV p p 500 Hz sine Check for 100 mV p p GAIN X100 wave signal to the PROBE INPUTS 500 Hz undistorted si...

Page 13: ...UT OFF setting the signal at OUTPUT should be 1 V In contrast when the signal frequency is decreased below the LOW CUT OFF setting the signal at OUTPUT will approach 0 V As the input signal frequency is increased above the HIGH CUT OFF setting the signal at OUTPUT will also approach 0 V High Frequency Cut Off Filter Controls Inputs Observations Adjust Check LOW CUT OFF 10 HZ Apply 1 mV p p sine wa...

Page 14: ...e Repeat this test for each NOTCH setting Each time begin with the input signal at 10 Hz and then increase it to 100 Hz With NOTCH OUT the signal at OUTPUT should remain 1 V With NOTCH IN the signal at OUTPUT should be substantially reduced around 60 Hz or 50 Hz if your instrument has been factory preset for a 50 Hz environment and less so above and below this frequency 01 Hz 1 Hz 10 Hz 100 Hz 1 k...

Page 15: ...egrated circuit and test point locations are shown in the following figure NOTE It is important to complete this entire procedure in sequence If any adjustment is made all of the following adjustments must be made in order to ensure that the specifications will be met CAUTION Do not open the HeadStage probe for any of these proceedures T101 R L 15 A400 A401 A 40 2 T P400 T300 A30 0 T P300 A3 01 A ...

Page 16: ...tive devices Please properly ground yourself and your workstation before removing any components Follow PROCEDURE A below for each operational amplifier listed Channel 1 A100 A101 A102 A103 A400 A401 A402 HeadStage A1 Test at locations CR100 15 V and CR101 15 V Channel 2 A200 A201 A202 A203 A500 A501 A502 HeadStage A1 Test at locations CR200 15 V and CR201 15 V Common A300 pins 4 and 8 15 V do not...

Page 17: ...ve op amp POWER ON Observe voltage on pin 4 Check for 15 V of the op amp socket Observe voltage on pin 7 Check for 15 V of the op amp socket POWER OFF Replace op amp or remove an additional op amp for further testing POWER ON Zeroing The following procedure calibrates Channel 1 Controls Inputs Observations Adjust Check POWER ON Connect PROBE and PROBE Adjust T100 for 0 0 V to instrument GND Observ...

Page 18: ...owing proceedure calibrates Channel 1 Controls Inputs Observations Adjust Check MODE REC Apply a 1 mV p p 1 kHz signal HIGHCUT OFF 10KHZ between PROBE and PROBE LOW CUT OFF 100 HZ Observe voltage at RL11 pin 8 Check for 5 mV p p at and RL11 pin 9 both pins and 180 degree phase shift between pins Observe voltage at TP100 Check for 10 mV p p Observe voltage at TP101 Check for 100 mV p p NOTCH IN Obs...

Page 19: ...tage should not be a clean undistorted sine wave due to the balanced gains of the differential amplifier Repeat this proceedure for locations TP200 and T201 to calibrate Channel 2 Impedance Current Injection Controls Inputs Observations Adjust Check Observe TP300 with an Adjust T300 for a maximum oscilloscope p p output Check that the output signal is 1 kHz Observe voltage at OUTPUT Adjust T301 fo...

Page 20: ...ance Input Output impedance ratio 1 M 0 1 V Maximum output impedance reading 4 V or 40 M General Electrical Input impedance 100 000 M typical Output Impedance 1 Common mode rejection Adjustable to better than 80 dB Notch Filter Better than 30 dB at 60 Hz Better than 25 dB at 50 Hz Input bias current 200 pA typical DC Compliance range At least 1 V DC Output dynamic range 10 V AC minimum Low cut off...

Page 21: ...dware to A M Systems must be prepaid by the Purchaser and all risk for the hardware shall remain with purchaser until such time as A M Systems takes receipt of the hardware Upon receipt A M Systems will promptly repair or replace the defective unit and then return the hardware or its replacement to the Purchaser postage shipping and insurance prepaid A M Systems may use reconditioned or like new p...

Page 22: ...cluding or limiting liability for incidental or consequential damages Check the provision of your local jurisdiction to find out whether the above exclusion applies to you This warranty allocates risks of product failure between the Purchaser and A M Systems A M Systems hardware pricing reflects this allocation of risk and the limitations of liability contained in this warranty The agents employee...

Page 23: ...A M Systems Model 1800 Manual DRW 5026500 rev 8 Revision History Rev Date Description 7 6 30 06 Initial Document Control release 8 4 28 10 DCR201200 Warranty and Company Information ...

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