BIOPAC® Systems, Inc. Logo

How should I prepare electrode sites?

For most biopotential recordings, it is important to provide a low impedance contact with the tissue underneath the skin at the electrode site. Consequently skin should be abraded with pumice, an ELPAD or ELPREP. Alcohol prep pads are generally not preferred because they dry the skin. The purpose of abrasion is to remove dead cells from the outer layer of skin. These cells form an electrical barrier. Electrical communication from the electrode surface to the underlying tissue is most often through a water-based gel. For good recordings, this gel must soak into the skin. As alcohol dries out the skin, it slows the process of establishing the liquid bridge between electrode and tissue.

One exception where abrasion is not recommended is measurement of electrodermal activity (skin conductance). Here skin should be rinsed but neither washed with soap nor abraded. As the conductivity of the skin at the electrode site is the variable to be measured in this case, no steps should be taken to modify that conductance artificially.

Spotlight On
free BIOPAC webinar

New Scent Delivery System for Research

Researchers can now easily add an olfactory element to expand general psychophysiology studies, enrich virtual and augmented environments, or examine how scent perception affects a variety of applications. BIOPAC’s new Scent Delivery System (SDS200-SYS), connects to an MP160 Research System with AcqKnowledge, and delivers up to eight scents to participants.

You Will Learn How To:
• Add olfactory stimulation to any experiment
• Optimize setup to get the best results
• Combine different types of stimulation

LIVE WEBINAR on November 4 at 8AM PT/11AM ET

Register Now
Latest News

New Citations | Physiological Measures to Understand Stress

BIOPAC provides software and hardware that allows research teams to study physiological measures related to stress. Here are a few notable studies using BIOPAC equipment for ECG, EDA, and EEG/ERP. Moms Moderating Stress Can relaxation techniques help lower stress on both mother and fetus? Using an MP36R Data Acquisition system to record ECG and EDA, this study […]

Electrocardiography Guide Now Available

BIOPAC’s comprehensive Introductory ECG Guide addresses fundamental to advanced concerns to optimize electrocardiography data recording and analysis. Topics include: ECG Complex; Electrical and Mechanical Sequence of a Heartbeat; Systole and Diastole; Configurations for Lead I, Lead II, Lead III, 6-lead ECG, 12-lead ECG, precordial leads; Ventricular Late Potentials (VLPs); ECG Measurement Tools; Automated Analysis Routines for extracting, […]

Read All
Request a Demonstration
Request a Demonstration