Information

Where should I place a reference electrode?

Where should I place a reference electrode?

This site gives basics of how to place electrodes for action potential recording. What I understand is that in order to get better signal, the reference electrode must be placed where there is minimum electrical activity. So, does that mean we can leave it hanging in the air, or attach it to a wooden surface?


Short answer
In general, a reference electrode should be placed in a well-conducting medium close, or some distance away from the recording electrode.

Background
The idea of a reference electrode is that it picks up any unwanted signals, such as artifacts, that are also present on the recording electrode. Background noise and artifacts can ruin the electrophysiological signal.

As your linked web page explains nicely, a well-placed reference electrode can mitigate noise and artifacts. In the linked page they take the example of recording motoneurons in muscle. If you would place the active electrode in the nerve close to the muscle, and the reference electrode away from the nerve but still close to the muscle, any artifacts arising from, e.g., muscle activity are picked up by the active and reference electrodes simultaneously. The closer the reference electrode is to the recording electrode, the larger the similarity of the artifact will be and the lesser the contamination. This effect can be achieved using a differential amplifier. The subtraction of the reference signal is referred to as common-mode rejection (Kappenman & Luck, 2011).

The terminology encountered is often referred to as monopolar recording and bipolar recording setups (e.g. Beck et al., 2007). Monopolar recordings use a distant reference electrode. This setup comes in handy when the potentials of interest are small and the preparation is devoid of artifacts. Because the distant reference electrode will almost pick up none of the signal, the signal is nicely preserved. However, any local artifacts will not be cancelled out. In case of artifacts and background noise, a bipolar setup is preferred by placing the reference close to the recording electrode. The signal amplitude may drop, but the added benefit of noise cancellation may outweigh that loss. Basically it is a trade-off to optimize the signal-to-noise ratio.

An electrophysiology amplifier records potentials (or currents). This requires a closed system that allows the passage of current through the system (Fig. 1). Large impedances will result in current flow to be minimal and hence the potentials cannot be picked up anymore. As a rule of thumb, in case of EEG recordings and other compound-action potential recordings as in your linked page, low-impedance measurements are best. Therefore, placing the reference on a high-impedance surface as suggested in the question (suspended in air or fastened to an insulator like wood) is the worst thing you can do.


Fig. 1. Diagram of an electrophysiological recording setup. source: InTech. Note that the reference electrode here is called a reference electrode. The terminology on your linked web page is likewise confusing as they call the reference electrode the ground electrode. A ground electrode is, however, different from the reference electrode, as the ground electrode is used to reduce outside influences on your signal, like the 50-Hz mains power or other electrical field emanating from equipment and so forth.

In addition, for the most optimal recordings, impedances should be matched between active and reference electrode (Kappenman & Luck, 2011). When there is a large mismatch between them, common-mode rejection works less effectively and the signal-to-noise ratio (SNR) will decrease. Therefore, placing the active electrode in tissue (low impedance) and the other one in a high-impedance medium will result in the common-mode rejection to fail.

References
- Beck et al., J Neurosci Methods (2007); 166(2): 159-67
- Kappenman & Luck, Psychophysiology (2010); 47(5): 888-904


A Review on Nerve Conduction Studies Volume 1 - Issue 3

Electrophysiological measurements are indispensable tool for investigating the functional integrity of peripheral nerves in both clinical and laboratory environments. Nerve conduction study is a property of both the axons and myelin sheath. The nerve conduction velocity is highly dependent on rapid signal propagation enabled by myelination. The compound motor action potential (CMAP) which correlates with the number of functional axons is an indicator for axonal damage when significantly reduced. Because nerve conduction velocity (NCV) is sensitive to both myelin sheath and axonal changes, it is an excellent measure of the function of the peripheral nervous system. Nerve conduction studies may be diagnostically helpful in patients suspected of having almost any peripheral nervous system disorder including disorders of nerve roots, peripheral nerves, muscle and neuromuscular junction. Cranial nerves and spinal cord function may also be assessed. Here, we mentioned the components and properties of nerve conduction study.

Keywords: Amplitude Compound Motor Action Potential Late Response Latency Nerve Conduction Study Nerve Conduction Velocity Sensory Nerve Action Potential


3 Answers 3

If you only have three wires coming from the meter, and four going to the "main" panel. Then you're going to bond the neutral in the disconnect enclosure, so the direct answer to your question is all 3.

If there's a grounding bus bar in the enclosure, you'll terminate the grounding electrode conductor (the other end of which is attached to the grounding electrode) at the grounding bar. Otherwise, you'll just pull it into the box.

Next you'll bond the box itself, by connecting a conductor from the box to the grounding bar (or grounding electrode conductor, if there's no bus bar). This may be done already, depending on how the bus bar attaches to the box. If the bus bar is bonded via the attachment method, you're done with this step.

You're also going to bond the service neutral in this box. This will be done via a bonding jumper between the neutral bus bar and the grounding bus bar, or by connecting a conductor between the neutral bus bar and the grounding electrode conductor.

You'll connect the grounding conductor going to the "main" panel, to the grounding bus bar or the grounding electrode conductor.

When you're done the service neutral will be bonded, so it should be isolated from the grounding conductor everywhere else in the building.

You'll end up with something that looks like this.


Reference list citations start with Author information. Since Author information comes first, it is the first component that your readers will identify and therefore needs to tie most directly to the In-text citation. In this regard it is the main identifying component.

Examples:

Formatting Author information:

Always list the author's surname before listing his or her initials.

You only need to provide initials for the first and middle names, but do include initials for all middle names provided by the source.

Include a comma after every last name and in-between different authors' names. Include a period after every initial. Always close the Author portion of the citation with one period. See examples above.

APA Manual p. 184, Section 6.27


Quickstart Guide: Versatile 32

Step 1: Preparation

  1. Select the cap to use:


Measure the circumference of the head and choose the correct cap for the participant. For more information about cap sizes, see Head Size and Versatile EEG

Sockets will be used for sensor placement and should be added in the desired positions. Sockets go into the small labeled holes. Slightly enlarge the hole with your finger, then insert the socket from the inside of the cap outwards, until the fabric falls into the slot on the socket.

Sockets only need to be removed if you plan to change sensor locations.

If you have more than one ongoing experiment that requires different sensor locations, consider purchasing an additional cap with more sockets.

Note: Take note of the positions of each numbered channel. This will be required for proper data analysis.

Step 2: Participant Setup


Squeeze out excess water from the dampened reference sponge (smaller, and green), then place it into the holder on the inner part of the reference clip, next to the metal sensor.


If you are using the short cable harness, the amplifier is attached to the back of the head via Velcro patch.

Step 3: Power Up, Connect to Software

  1. Power up the amplifier:

Hold the power button until the LED blinks. This will turn steady when a connection is established with the Bitbrain Device Viewer acquisition software. If the device is already paired with the computer, skip to step 3.

The amplifier must be paired with the Bluetooth receiver on the Windows computer or tablet that will run the acquisition software. This requires Bluetooth version 2.1 or higher.

When doing this for the first time, press the Windows Key and type "Settings". Choose "Devices" from the list and select "Add Bluetooth or other device". The name of the Versatile amplifier in the list of available devices will correspond to the serial number listed on the product label of the amplifier itself.


Run the Bitbrain Device Viewer software. Click "Connect" to establish a connection. Choose "Bluetooth" then select the device from the drop-down menu. The device name will correspond to the serial number listed on the product label of the Versatile amplifier.

Step 4: Check Signal Quality and Start Acquisition

  1. Verify signal quality:

    Wait a few moments for the signal to stabilize. Individual electrodes are color coded by impedance level. Channels listed as "green" are giving good signal quality and are ready for data acquisition. Red or yellow channels should be corrected where possible.


First: gently push on the sensor against the scalp making a small circular motion to help improve contact and to get through hair. Wait several seconds and check the signal quality.


Second: If that didn't work, remove the electrode from the socket by gently pulling backwards with slight rotation. Do not remove by pulling on the cable. Verify that the sponge is damp enough, re-wet with tap water and replace the electrode. Wait several seconds and check the signal quality.

Data can be recorded to an on-board memory card, and/or streamed and recorded to the computer or tablet running the Bitbrain Device Viewer software.

To record data to the microSD card, check "SD card record". Be sure to use an appropriate memory card.

To record data to the computer hard drive, click "Hard drive record". Remember that hard drive recording can be interrupted if the participant leaves Bluetooth transmission range.

Select "Enable LSL Server" to use LSL-compatible features in the software developer kit.


An increment of 3cm for every x coordinate (x=0, 3, 6, 9, 12, and 15) and voltage readings of .25, .30, .50, .75, and 1.00 will be measured. Below are two tables (because two different metal plates are used) of data that illustrate the voltage readings collected during the experiment. The readings on the voltmeter measure the electric potential of two different charge distributions and this measurement can be used to find the electric field. Electric field lines starts on a positive charge and end on a negative charge. The number of electric field lines tells us the amount of

The % removals of Chemical Oxidation Demand (COD) were calculated by changing different parameters: pH, electrode gap and operation time. 2.2Materials: Sample for experiment were collected from ABC Barings Ltd. Oily Wastewater generated in Heat Section of


Discussion / Further Work

  1. The documented record of most days without sleep was made by high school student Randy Gardner when he went for 11 days without sleep in San Diego in 1964. But this is a dangerous record to try to break, so don't try it (and Guinness no longer keeps track).
  2. You may have noticed the EEG during is much stronger and more obvious in the delta waves of sleep than during awake EEG. Why do you think that is?
  3. Ever wondered how coffee works? We feel tired after being awake for a while, as the build-up of adenosine produced by neurons in our brain indicates the need for us to sleep. Caffeine blocks the adenosine receptors in your brain.
  4. We have found that our EEG headband works best for naps, but doesn’t stay situated correctly overnight. Most overnight sleep involves body movement that shifts the headband and and releases the electrode connection. Perhaps you could design a better way to keep the headband in place during the night with hair clips and a modification of the electrodes.
  5. Finally, EEG is wonderful to measure, but novices may find the low signal strength surprising (and perhaps disappointing). EEG is one of the weaker electrophysiological signals, and it is important to remain still (don't move any muscle of the head) and reduce noise as much as possible. See figure below that illustrates the EEG signal strength compared to other signals we can measure with the Heart and Brain SpikerBox.


Biopotential Recording is an important parameter in studying, discovering, and diagnosing neurological disorders. Electroencephalogram (EEG) is recording of electrical activity of the human brain, typically performed, using surface electrodes. Commercial wet Ag/AgCl electrodes are the gold standard among surface electrodes. Nevertheless, these electrodes are inappropriate in wearable long-term applications mainly due to the use of conductive gels and inflexibility. Various types of dry electrodes are proposed in the literature to address the inherent disadvantages of wet electrodes. Yet few works in the state-of-the-art address mechanical reliability tests which is of paramount importance in real world wearable applications.

In this manuscript, we have demonstrated a relatively inexpensive flexible and stretchable dry electrode to record the EEG. The electrode is formed in a 3D shape with 4 legs in order to increase the compliance to the skin as well as mechanical and electrical reliability. The electrical performance of the electrode is found to be similar to the standard wet Ag/AgCl counterpart. In addition to the typical tensile strength test, the mechanical endurance of the electrode is verified using a custom-designed stroke test in a relatively severe condition.


Quickstart Guide: Versatile 16

Step 1: Preparation

  1. Select the cap to use:


Measure the circumference of the head and choose the correct cap for the participant. For more information about cap sizes, see Head Size and Versatile EEG

Sockets will be used for sensor placement and should be added in the desired positions. Sockets go into the small labeled holes. Slightly enlarge the hole with your finger, then insert the socket from the inside of the cap outwards, until the fabric falls into the slot on the socket.

Sockets only need to be removed if you plan to change sensor locations.

If you have more than one ongoing experiment that requires different sensor locations, consider purchasing an additional cap with more sockets.

Note: Take note of the positions of each numbered channel. This will be required for proper data analysis.

Step 2: Participant Setup


Squeeze out excess water from the dampened reference sponge (smaller, and green), then place it into the holder on the inner part of the reference clip, next to the metal sensor.


If you are using the short cable harness, the amplifier is attached to the back of the head via Velcro patch.

Step 3: Power Up, Connect to Software

  1. Power up the amplifier:

Hold the power button until the LED blinks. This will turn steady when a connection is established with the Bitbrain Device Viewer acquisition software. If the device is already paired with the computer, skip to step 3.

The amplifier must be paired with the Bluetooth receiver on the Windows computer or tablet that will run the acquisition software. This requires Bluetooth version 2.1 or higher.

When doing this for the first time, press the Windows Key and type "Settings". Choose "Devices" from the list and select "Add Bluetooth or other device". The name of the Versatile amplifier in the list of available devices will correspond to the serial number listed on the product label of the amplifier itself.


Run the Bitbrain Device Viewer software. Click "Connect" to establish a connection. Choose "Bluetooth" then select the device from the drop-down menu. The device name will correspond to the serial number listed on the product label of the Versatile amplifier.

Step 4: Check Signal Quality and Start Acquisition

  1. Verify signal quality:

    Wait a few moments for the signal to stabilize. Individual electrodes are color coded by impedance level. Channels listed as "green" are giving good signal quality and are ready for data acquisition. Red or yellow channels should be corrected where possible.


First: gently push on the sensor against the scalp making a small circular motion to help improve contact and to get through hair. Wait several seconds and check the signal quality.


Second: If that didn't work, remove the electrode from the socket by gently pulling backwards with slight rotation. Do not remove by pulling on the cable. Verify that the sponge is damp enough, re-wet with tap water and replace the electrode. Wait several seconds and check the signal quality.

Data can be recorded to an on-board memory card, and/or streamed and recorded to the computer or tablet running the Bitbrain Device Viewer software.

To record data to the microSD card, check "SD card record". Be sure to use an appropriate memory card.

To record data to the computer hard drive, click "Hard drive record". Remember that hard drive recording can be interrupted if the participant leaves Bluetooth transmission range.

Select "Enable LSL Server" to use LSL-compatible features in the software developer kit.


Occipital and Supraorbital Nerve Stimulator Placement

Indications

Peripheral nerve stimulation (PNS) is indicated for patients with chronic, medically refractory, severe neuropathic pain that involves distribution of the nerve to be stimulated.

Occipital nerve stimulation (ONS) is indicated primarily for treatment of occipital neuralgia, including posttraumatic and postsurgical pain in the occipital nerve distribution.

Supraorbital nerve stimulation (SNS) is indicated for patients with trigeminal neuropathic pain, mainly secondary to posttraumatic or postsurgical supraorbital neuralgia or neuropathy (e.g., after operations on frontal sinuses, after frontal craniotomies).

ONS and SNS have been used for treatment of migraines and cluster headaches in research studies.


Occipital and Supraorbital Nerve Stimulator Placement

Indications

Peripheral nerve stimulation (PNS) is indicated for patients with chronic, medically refractory, severe neuropathic pain that involves distribution of the nerve to be stimulated.

Occipital nerve stimulation (ONS) is indicated primarily for treatment of occipital neuralgia, including posttraumatic and postsurgical pain in the occipital nerve distribution.

Supraorbital nerve stimulation (SNS) is indicated for patients with trigeminal neuropathic pain, mainly secondary to posttraumatic or postsurgical supraorbital neuralgia or neuropathy (e.g., after operations on frontal sinuses, after frontal craniotomies).

ONS and SNS have been used for treatment of migraines and cluster headaches in research studies.


Biopotential Recording is an important parameter in studying, discovering, and diagnosing neurological disorders. Electroencephalogram (EEG) is recording of electrical activity of the human brain, typically performed, using surface electrodes. Commercial wet Ag/AgCl electrodes are the gold standard among surface electrodes. Nevertheless, these electrodes are inappropriate in wearable long-term applications mainly due to the use of conductive gels and inflexibility. Various types of dry electrodes are proposed in the literature to address the inherent disadvantages of wet electrodes. Yet few works in the state-of-the-art address mechanical reliability tests which is of paramount importance in real world wearable applications.

In this manuscript, we have demonstrated a relatively inexpensive flexible and stretchable dry electrode to record the EEG. The electrode is formed in a 3D shape with 4 legs in order to increase the compliance to the skin as well as mechanical and electrical reliability. The electrical performance of the electrode is found to be similar to the standard wet Ag/AgCl counterpart. In addition to the typical tensile strength test, the mechanical endurance of the electrode is verified using a custom-designed stroke test in a relatively severe condition.


Quickstart Guide: Versatile 16

Step 1: Preparation

  1. Select the cap to use:


Measure the circumference of the head and choose the correct cap for the participant. For more information about cap sizes, see Head Size and Versatile EEG

Sockets will be used for sensor placement and should be added in the desired positions. Sockets go into the small labeled holes. Slightly enlarge the hole with your finger, then insert the socket from the inside of the cap outwards, until the fabric falls into the slot on the socket.

Sockets only need to be removed if you plan to change sensor locations.

If you have more than one ongoing experiment that requires different sensor locations, consider purchasing an additional cap with more sockets.

Note: Take note of the positions of each numbered channel. This will be required for proper data analysis.

Step 2: Participant Setup


Squeeze out excess water from the dampened reference sponge (smaller, and green), then place it into the holder on the inner part of the reference clip, next to the metal sensor.


If you are using the short cable harness, the amplifier is attached to the back of the head via Velcro patch.

Step 3: Power Up, Connect to Software

  1. Power up the amplifier:

Hold the power button until the LED blinks. This will turn steady when a connection is established with the Bitbrain Device Viewer acquisition software. If the device is already paired with the computer, skip to step 3.

The amplifier must be paired with the Bluetooth receiver on the Windows computer or tablet that will run the acquisition software. This requires Bluetooth version 2.1 or higher.

When doing this for the first time, press the Windows Key and type "Settings". Choose "Devices" from the list and select "Add Bluetooth or other device". The name of the Versatile amplifier in the list of available devices will correspond to the serial number listed on the product label of the amplifier itself.


Run the Bitbrain Device Viewer software. Click "Connect" to establish a connection. Choose "Bluetooth" then select the device from the drop-down menu. The device name will correspond to the serial number listed on the product label of the Versatile amplifier.

Step 4: Check Signal Quality and Start Acquisition

  1. Verify signal quality:

    Wait a few moments for the signal to stabilize. Individual electrodes are color coded by impedance level. Channels listed as "green" are giving good signal quality and are ready for data acquisition. Red or yellow channels should be corrected where possible.


First: gently push on the sensor against the scalp making a small circular motion to help improve contact and to get through hair. Wait several seconds and check the signal quality.


Second: If that didn't work, remove the electrode from the socket by gently pulling backwards with slight rotation. Do not remove by pulling on the cable. Verify that the sponge is damp enough, re-wet with tap water and replace the electrode. Wait several seconds and check the signal quality.

Data can be recorded to an on-board memory card, and/or streamed and recorded to the computer or tablet running the Bitbrain Device Viewer software.

To record data to the microSD card, check "SD card record". Be sure to use an appropriate memory card.

To record data to the computer hard drive, click "Hard drive record". Remember that hard drive recording can be interrupted if the participant leaves Bluetooth transmission range.

Select "Enable LSL Server" to use LSL-compatible features in the software developer kit.


Reference list citations start with Author information. Since Author information comes first, it is the first component that your readers will identify and therefore needs to tie most directly to the In-text citation. In this regard it is the main identifying component.

Examples:

Formatting Author information:

Always list the author's surname before listing his or her initials.

You only need to provide initials for the first and middle names, but do include initials for all middle names provided by the source.

Include a comma after every last name and in-between different authors' names. Include a period after every initial. Always close the Author portion of the citation with one period. See examples above.

APA Manual p. 184, Section 6.27


A Review on Nerve Conduction Studies Volume 1 - Issue 3

Electrophysiological measurements are indispensable tool for investigating the functional integrity of peripheral nerves in both clinical and laboratory environments. Nerve conduction study is a property of both the axons and myelin sheath. The nerve conduction velocity is highly dependent on rapid signal propagation enabled by myelination. The compound motor action potential (CMAP) which correlates with the number of functional axons is an indicator for axonal damage when significantly reduced. Because nerve conduction velocity (NCV) is sensitive to both myelin sheath and axonal changes, it is an excellent measure of the function of the peripheral nervous system. Nerve conduction studies may be diagnostically helpful in patients suspected of having almost any peripheral nervous system disorder including disorders of nerve roots, peripheral nerves, muscle and neuromuscular junction. Cranial nerves and spinal cord function may also be assessed. Here, we mentioned the components and properties of nerve conduction study.

Keywords: Amplitude Compound Motor Action Potential Late Response Latency Nerve Conduction Study Nerve Conduction Velocity Sensory Nerve Action Potential


Quickstart Guide: Versatile 32

Step 1: Preparation

  1. Select the cap to use:


Measure the circumference of the head and choose the correct cap for the participant. For more information about cap sizes, see Head Size and Versatile EEG

Sockets will be used for sensor placement and should be added in the desired positions. Sockets go into the small labeled holes. Slightly enlarge the hole with your finger, then insert the socket from the inside of the cap outwards, until the fabric falls into the slot on the socket.

Sockets only need to be removed if you plan to change sensor locations.

If you have more than one ongoing experiment that requires different sensor locations, consider purchasing an additional cap with more sockets.

Note: Take note of the positions of each numbered channel. This will be required for proper data analysis.

Step 2: Participant Setup


Squeeze out excess water from the dampened reference sponge (smaller, and green), then place it into the holder on the inner part of the reference clip, next to the metal sensor.


If you are using the short cable harness, the amplifier is attached to the back of the head via Velcro patch.

Step 3: Power Up, Connect to Software

  1. Power up the amplifier:

Hold the power button until the LED blinks. This will turn steady when a connection is established with the Bitbrain Device Viewer acquisition software. If the device is already paired with the computer, skip to step 3.

The amplifier must be paired with the Bluetooth receiver on the Windows computer or tablet that will run the acquisition software. This requires Bluetooth version 2.1 or higher.

When doing this for the first time, press the Windows Key and type "Settings". Choose "Devices" from the list and select "Add Bluetooth or other device". The name of the Versatile amplifier in the list of available devices will correspond to the serial number listed on the product label of the amplifier itself.


Run the Bitbrain Device Viewer software. Click "Connect" to establish a connection. Choose "Bluetooth" then select the device from the drop-down menu. The device name will correspond to the serial number listed on the product label of the Versatile amplifier.

Step 4: Check Signal Quality and Start Acquisition

  1. Verify signal quality:

    Wait a few moments for the signal to stabilize. Individual electrodes are color coded by impedance level. Channels listed as "green" are giving good signal quality and are ready for data acquisition. Red or yellow channels should be corrected where possible.


First: gently push on the sensor against the scalp making a small circular motion to help improve contact and to get through hair. Wait several seconds and check the signal quality.


Second: If that didn't work, remove the electrode from the socket by gently pulling backwards with slight rotation. Do not remove by pulling on the cable. Verify that the sponge is damp enough, re-wet with tap water and replace the electrode. Wait several seconds and check the signal quality.

Data can be recorded to an on-board memory card, and/or streamed and recorded to the computer or tablet running the Bitbrain Device Viewer software.

To record data to the microSD card, check "SD card record". Be sure to use an appropriate memory card.

To record data to the computer hard drive, click "Hard drive record". Remember that hard drive recording can be interrupted if the participant leaves Bluetooth transmission range.

Select "Enable LSL Server" to use LSL-compatible features in the software developer kit.


An increment of 3cm for every x coordinate (x=0, 3, 6, 9, 12, and 15) and voltage readings of .25, .30, .50, .75, and 1.00 will be measured. Below are two tables (because two different metal plates are used) of data that illustrate the voltage readings collected during the experiment. The readings on the voltmeter measure the electric potential of two different charge distributions and this measurement can be used to find the electric field. Electric field lines starts on a positive charge and end on a negative charge. The number of electric field lines tells us the amount of

The % removals of Chemical Oxidation Demand (COD) were calculated by changing different parameters: pH, electrode gap and operation time. 2.2Materials: Sample for experiment were collected from ABC Barings Ltd. Oily Wastewater generated in Heat Section of


Discussion / Further Work

  1. The documented record of most days without sleep was made by high school student Randy Gardner when he went for 11 days without sleep in San Diego in 1964. But this is a dangerous record to try to break, so don't try it (and Guinness no longer keeps track).
  2. You may have noticed the EEG during is much stronger and more obvious in the delta waves of sleep than during awake EEG. Why do you think that is?
  3. Ever wondered how coffee works? We feel tired after being awake for a while, as the build-up of adenosine produced by neurons in our brain indicates the need for us to sleep. Caffeine blocks the adenosine receptors in your brain.
  4. We have found that our EEG headband works best for naps, but doesn’t stay situated correctly overnight. Most overnight sleep involves body movement that shifts the headband and and releases the electrode connection. Perhaps you could design a better way to keep the headband in place during the night with hair clips and a modification of the electrodes.
  5. Finally, EEG is wonderful to measure, but novices may find the low signal strength surprising (and perhaps disappointing). EEG is one of the weaker electrophysiological signals, and it is important to remain still (don't move any muscle of the head) and reduce noise as much as possible. See figure below that illustrates the EEG signal strength compared to other signals we can measure with the Heart and Brain SpikerBox.


3 Answers 3

If you only have three wires coming from the meter, and four going to the "main" panel. Then you're going to bond the neutral in the disconnect enclosure, so the direct answer to your question is all 3.

If there's a grounding bus bar in the enclosure, you'll terminate the grounding electrode conductor (the other end of which is attached to the grounding electrode) at the grounding bar. Otherwise, you'll just pull it into the box.

Next you'll bond the box itself, by connecting a conductor from the box to the grounding bar (or grounding electrode conductor, if there's no bus bar). This may be done already, depending on how the bus bar attaches to the box. If the bus bar is bonded via the attachment method, you're done with this step.

You're also going to bond the service neutral in this box. This will be done via a bonding jumper between the neutral bus bar and the grounding bus bar, or by connecting a conductor between the neutral bus bar and the grounding electrode conductor.

You'll connect the grounding conductor going to the "main" panel, to the grounding bus bar or the grounding electrode conductor.

When you're done the service neutral will be bonded, so it should be isolated from the grounding conductor everywhere else in the building.

You'll end up with something that looks like this.


Watch the video: Ένα ΚΟΠΑΔΙ Μαγιάτικα (January 2022).