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Go Direct® Electrode Amplifier User Manual

Order Code: GDX-EA

Use our Go Direct Electrode Amplifier to collect data with almost any electrode that has a BNC connector. This includes electrodes from Vernier, such as our pH electrodes, ion-selective electrodes (ISE), or oxidation-reduction potential (ORP) electrode. The Go Direct Electrode Amplifier can produce an output in mV, pH (when using a pH electrode).

Note: Vernier products are designed for educational use. Our products are not designed nor are they recommended for any industrial, medical, or commercial process such as life support, patient diagnosis, control of a manufacturing process, or industrial testing of any kind.

What's Included

  • Go Direct Electrode Amplifier
  • Micro USB Cable

Compatible Software

Choose a platform below to see its compatibility requirements.

LabQuest
InterfaceLabQuest App
LabQuest 3Full support 1
LabQuest 2 (discontinued)Full support 1 2
LabQuest (discontinued)Incompatible

Compatibility Notes

  1. Requires a BNC electrode
  2. Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter when used with some older LabQuest 2 models.
Computers
Software
InterfaceGraphical Analysis
No interface requiredFull support 1 2
LabQuest 3Full support 1 3
LabQuest 2 (discontinued)Full support 1 3 4

Compatibility Notes

  1. Requires a BNC electrode
  2. For Bluetooth® connectivity, only computers running Windows 10 or Mac OS X 10.10 or newer are supported. The computer must also have a compatible Bluetooth 4.0+ radio.
  3. Connect this sensor directly to a computer or Chromebook via a USB or wireless Bluetooth® connection for best results. Alternatively, this sensor is fully supported when used with LabQuest 2 or LabQuest 3 when the LabQuest is connected to a computer or Chromebook via Wireless Data Sharing.
  4. Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter when used with some older LabQuest 2 models.
Chromebook
Software
InterfaceGraphical Analysis
No interface requiredFull support 1
LabQuest 3Full support 1 2
LabQuest 2 (discontinued)Full support 1 2 3

Compatibility Notes

  1. Requires a BNC electrode
  2. Connect this sensor directly to a computer or Chromebook via a USB or wireless Bluetooth® connection for best results. Alternatively, this sensor is fully supported when used with LabQuest 2 or LabQuest 3 when the LabQuest is connected to a computer or Chromebook via Wireless Data Sharing.
  3. Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter when used with some older LabQuest 2 models.
iOS
Software
InterfaceGraphical AnalysisGraphical Analysis GW
No interface requiredFull support 1Full support 1
LabQuest 3Full support 1 2 3Full support 1 2 3
LabQuest 2 (discontinued)Full support 1 2 3 4Full support 1 2 3 4

Compatibility Notes

  1. Requires a BNC electrode
  2. Connect this sensor directly to a supported mobile device via a wireless Bluetooth® connection for best results.
  3. iOS and Androidâ„¢ devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.
  4. Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter when used with some older LabQuest 2 models.
Android
Software
InterfaceGraphical AnalysisGraphical Analysis GW
No interface requiredFull support 1Incompatible 1
LabQuest 3Full support 2 3Full support 1 2
LabQuest 2 (discontinued)Full support 2 3 4Full support 1 2 4

Compatibility Notes

  1. Requires a BNC electrode
  2. iOS and Androidâ„¢ devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.
  3. Connect this sensor directly to a supported mobile device via a wireless Bluetooth® connection for best results.
  4. Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter when used with some older LabQuest 2 models.
Python
Software
InterfacePython
No interface requiredFull support
Javascript
Software
InterfaceJavascript
No interface requiredFull support 1

Compatibility Notes

  1. A wireless Bluetooth® connection can be made with Go Direct sensors on any platform running a browser with WebBluetooth support. However, only a few operating systems have been tested and testing has been limited.
LabVIEW
Software
InterfaceNI LabVIEW
No interface requiredFull support 1

Compatibility Notes

  1. For Bluetooth® connectivity, only computers running Windows 10 or Mac OS X 10.10 or newer are supported. The computer must also have a compatible Bluetooth 4.0+ radio.

Quick Start: Vernier Graphical Analysis® and Bluetooth®

  1. Connect a BNC electrode to the amplifier.
  2. Charge your sensor for at least 2 hours before first use.
  3. Turn on your sensor. The LED will blink red.
  4. Launch Graphical Analysis, then click Sensor Data Collection.
  5. Select your sensor from the list. The sensor ID is located on the sensor label near the bar code. Note: If you don’t see a list of available sensors, click WIRELESS. After selecting your sensor, click Pair.
  6. This is a multi-channel sensor. Click SENSOR CHANNELS and select the channel(s) you want to use.
  7. Click DONE. You are now ready to collect data.

Using other Vernier data-collection apps or want to connect via USB?

Visit www.vernier.com/start-go-direct

Note: This sensor also works with LabQuest 2 and LabQuest 3; it does not work with the original LabQuest.

Charging the Sensor

Connect the Go Direct Electrode Amplifier to the included USB micro cable and any USB device for two hours.

You can also charge up to eight Go Direct Electrode Amplifiers using our Go Direct Charge Station, sold separately (order code: GDX-CRG).

Charging

Blue LED is on steady while sensor is connected to the Charging Cable or Charge Station.
Fully charged

Blue LED is off when charging is complete.

Powering the Sensor

Turning on the sensor

Press button once. Red LED indicator flashes when unit is on.
Putting the sensor in sleep mode

Press and hold button for more than three seconds to put into sleep mode. Red LED indicator stops flashing when sleeping.

Connecting the Sensor

See the following link for up-to-date connection information:

www.vernier.com/start/gdx-ea

Connecting via Bluetooth

Ready to connect Red LED flashes when sensor is awake and ready to connect.
Connected Green LED flashes when sensor is connected via Bluetooth.

Connecting via USB

Connected and charging Blue and Green LEDs are solid when sensor is connected to Graphical Analysis via USB and unit is charging. (Green LED is obscured by the blue one.)
Connected, fully charged Green LED is solid when sensor is connected to Graphical Analysis via USB and the unit is fully charged.
Charging via USB,
connected via Bluetooth		 Blue LED is solid and green LED is flashing, but the green flashing LED looks white because it is overwhelmed by the blue.

Using the Product

Connect the sensor following the steps in the Quick Start section of this user manual.

Channels

Go Direct Electrode Amplifier has two measurement channels:

  • Potential
  • pH

Calibration

If a pH electrode is attached, a two-point calibration is recommended for the most accurate results. It is a simple process that takes only a few minutes. For additional calibration information, see www.vernier.com/til/4011

In order to calibrate a pH electrode/electrode amplifier combination, or to confirm that a saved pH calibration is accurate, you should have a supply of pH buffer solutions that cover the range of the pH values you will be measuring. For more information about pH buffer solutions, including recipes for preparation, see www.vernier.com/til/3625

Once you have calibrated a Go Direct sensor, the calibration is automatically stored to the sensor and will be used each time you connect to your device. You can always choose to restore factory defaults if you feel the custom calibration is invalid.

If an ORP or ion-selective electrode is connected and you are measuring potential, calibration is not required. Calibration is disabled in this mode to ensure the best results.

Specifications

Units

pH or mV

Input range (mV)

±1000 mV

Input range (pH)

0 to 14 pH

Accuracy with new electrode (mV)

±20 mV

Accuracy with new electrode (pH)

±0.2

Resolution

0.01 mV

Connections

Wireless

Wired

 

Bluetooth

USB

Care and Maintenance

Battery Information

Go Direct Electrode Amplifier contains a small lithium-ion battery in the handle. The system is designed to consume very little power and not put heavy demands on the battery. Although the battery is warranted for one year, the expected battery life should be several years. Replacement batteries are available from Vernier (order code: GDX-BAT-300).

Storage and Maintenance

To store Go Direct Electrode Amplifier for extended periods of time, put the device in sleep mode by holding the power button down for at least three seconds. The red LED will stop flashing to show that the unit is in sleep mode. Over several months, the battery will discharge but will not be damaged. After such storage, charge the device for a few hours, and the unit will be ready to go.

Exposing the battery to temperatures over 35°C (95°F) will reduce its lifespan. If possible, store the device in an area that is not exposed to temperature extremes.

Water Resistance

Go Direct Electrode Amplifier is not water resistant and should never be immersed in water.

If water gets into the device, immediately power the unit down (press and hold the power button for more than three seconds). Disconnect the sensor and charging cable, and remove the battery. Allow the device to dry thoroughly before attempting to use the device again. Do not attempt to dry using an external heat source.

How the Sensor Works

Go Direct Electrode Amplifier is a circuit that allows the voltage output of the electrode to be monitored. The electrode is connected to the BNC connector on one end of the amplifier.

Go Direct Electrode Amplifier will default to report values in units of pH. If an ORP or ISE electrode is attached, however, you can choose to read in units of mV. For additional information, see www.vernier.com/til/3984

Troubleshooting

For troubleshooting and FAQs, see www.vernier.com/til/3858

Repair Information

If you have followed the troubleshooting steps and are still having trouble with your Go Direct Electrode Amplifier, contact Vernier Technical Support at support@vernier.com or call 888-837-6437. Support specialists will work with you to determine if the unit needs to be sent in for repair. At that time, a Return Merchandise Authorization (RMA) number will be issued and instructions will be communicated on how to return the unit for repair.

Accessories/Replacements

Item Order Code

Go Direct pH BNC Electrode

GDX-PH-BNC

Go Direct ORP BNC Electrode

GDX-ORP-BNC

Go Direct Flat pH BNC Electrode

GDX-FPH-BNC

Go Direct Glass-Body pH BNC Electrode

GDX-GPH-BNC

Go Direct Potassium Ion-Selective Electrode BNC

GDX-K-BNC

Go Direct Nitrate Ion-Selective Electrode BNC

GDX-NO3-BNC

Go Direct Ammonium Ion-Selective Electrode BNC

GDX-NH4-BNC

Go Direct Chloride Ion-Selective Electrode BNC

GDX-CL-BNC

Go Direct Calcium Ion-Selective Electrode BNC

GDX-CA-BNC

Micro USB Cable

CB-USB-MICRO
Go Direct 300 mAh Replacement Battery

GDX-BAT-300
USB-C to Micro USB Cable

CB-USB-C-MICRO

Warranty

Warranty information for this product can be found on the Support tab at www.vernier.com/gdx-ea/#support

General warranty information can be found at www.vernier.com/warranty

Contact Support

Fill out our online support form or call us toll-free at 1-888-837-6437.

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