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EDA Electrodermal Activity GSR Galvanic Skin Response Amplifier

The EDA100C measures both the skin conductance level (SCL) and skin conductance response (SCR) as they vary with sweat gland (eccrine) activity due to stress, arousal or emotional excitement. The EDA100C uses a constant voltage (0.5 V) technique to measure skin conductance. The controls allow selection of absolute (SCL+SCR) or relative (SCR) skin conductance measurements.

For wireless Electrodermal Activity recording, see the BioNomadix BN-PPGED amplifier (dual-channel transmitter/receiver set for PPG and/or EDA).

automated skin conductance response scoring

AcqKnowledge software includes a fully automated electrodermal response scoring tool that locates skin conductance responses, visually identifies them in the record and measures them. It also automates event related potentials (ERP) analysis by locating the onset of the stimuli and identifying a valid SCR.

Use the Focus Areas analysis tool for targeted EDA Analysis. Focus Areas allow the user to specify and mark areas of interest in the data and then run automated analysis routines or the cycle detector specifically on the Focus Areas instead of the entire data file.

See Applications > Psychophysiology for further analysis information and advanced features.

Each EDA100C amplifier requires one set of the following electrode combinations:

  • 2 x LEAD110A Electrode Leads (recommended)
  • 2 x EL507 disposable Electrodermal Electrodes (recommended)


  • 1 x TSD203 Ag-AgCl Skin Conductance Transducer
  • 1 x GEL101 Electrodermal Gel


  • 2 x EL258 Ag-AgCl Lead Electrodes
  • 1 x ADD208 Adhesive Disks
  • 1 GEL101 Electrodermal Gel

Usage Recommendations

When using EL507 wait 5 minutes (minimum) before starting to record data. When using GEL101 it is important that the gel has a chance to be absorbed and make good contact before recording begins. Accordingly:

  1. Apply GEL101 to the skin at the point of electrode contact and rub it in.
  2. Fill the TSD203 electrode cavity with GEL101.
  3. Attach the TSD203 electrode to the subject.
  4. Wait 5 minutes (minimum) before starting to record data.


To set up AcqKnowledge to record skin conductance directly, perform the following:

Lower frequency response at DC

In the scaling window, set the input voltages so they map to the DC conductance ranges indicated by the sensitivity setting. For example, if the EDA100C is set to a Gain of 5 µmho/V, then 0 V will map to 0 µmhos or infinite resistance and 1 V will map to 5 µmho or 200 kΩ.

Lower frequency response at 0.05 Hz

In the scaling window, set the input voltages so they map to the 0.05 Hz conductance ranges indicated by the sensitivity setting. For example if the EDA100C is set to a Gain of 5 µmho/V, then 0V will map to X µmhos and 1 V will map to (X+5) µmhos, where X is the mean conductance being recorded.

To verify the Gain setting of the EDA100C:

  1. Calibrate AcqKnowledgeas detailed above for lower frequency response at DC.
  2. Place the lower frequency response to DC.
  3. Set the Gain switch on the EDA100C to 5 µmho/V.
  4. Perform measurement with electrodes disconnected.
    • AcqKnowledge should produce a reading of 0 µmho.
  5. Insulate a 100 kΩ resistor and place it from electrode pad to electrode pad (resistor must be insulated from fingers).
  6. Perform measurement with electrode-resistor setup.
    • AcqKnowledge should produce a reading of 10 µmho.
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 Magnetic Resonance Imaging with BIOPAC Equipment
     Electrodes, electrode leads, transducers, and stimulus options for safe data acquisition in the MRI. Record biopotentials, temperature, respiration, EDA, dynamometry, blood pressure, etc.
 Neuromarketing and Neuroeconomics
     Neuromarketing and neuroeconomics tools to study consumers' sensorimotor, cognitive, and affective response to marketing stimuli and decision making tasks. Use fNIR, MRI solutions, EEG, and wireless physiology.
 Noninvasive Blood Pressure Monitoring
     Human—continuous system with finger sensor. Fits children through large adults. MRI system also available. Animal—tail cuff sensor with automatic inflation.
     Record PPG, measure BP indirectly, look at appendage size variations, and perform sexual arousal studies using BIOPAC or 3rd-party transducers.
     Record and analyze BP, ECG, HRV, EDA, EMG, EEG, EOG, RSP, etc. Interface to stimulus presentation programs...use automated analysis routines to easily score and analyze data.

Knowledge Base Topics
Search the Knowledge Base or Ask a Question if your issue isn't listed here.
 AC mode
 Amplifier baseline offset adjustment
 Amplifier conversion - 2 mm to touchproof
 Amplifier filter settings
 Amplifier Module Filter Response Times
 Automated EDA scoring directions
 Automated scoring of electrodermal activity data
 Bilateral Electrodermal Activity
 DC mode
 Deep breath and SCR/EDA increase
 EDA (GSR) and grounding
 EDA (GSR) subject preparation
 EDA / SCR offset calibration for MRI
 Electrodermal activity measurements
 Galvanic Isolation Guidelines for the MP150 System
 Glossary of Specification Terminology
 Grounding guidelines
 Guidelines for GSR, EDA, EDR, SCL, and SCR
 Guidelines for Psychophysiological Recordings
 High pass filters
 Low pass filters
 Multiple amplifiers per subject or multiple subjects per system
 Negative (GSR)
 Notch filter
 Optimal ground placement
 Railing signal (flatline)
 Recording EDA (GSR) from multiple sites
 Reusable vs. disposable EDA/GSR electrodes
 Sample rates for different signals
 SCR and SCL measurement
 Signal drifts to zero
 Tutorial on Electrostatic Discharge
 Using BIOPAC research amplifiers with the BSL System

MP Systems Hardware Guide
AcqKnowledge 4 Software Guide
MP Research System User List
Application Note: GSR100C Electrodermal Response
Product Citations: review publications summary or conduct a search
MP Research Catalog
BioNomadix Wireless Physiology Catalog
New Products Catalog
MRI Catalog
VR and Stimulus Presentation Catalog
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