Go Direct^® Voltage Probe (GDX-VOLT)

Specifications and User Guide

Troubleshooting

General: Press the power button on the sensor to turn it on. Connect your sensor as described in the Getting Started instructions for your device.

• Primary test: When using Go Direct Voltage to measure electric potential, check the following:
  1. Are the leads properly and securely connected? The probe is designed to be used like voltmeter leads. It should be placed across a circuit element.
  2. Disconnect Go Direct Voltage from any power supplies and connect via Bluetooth. Electric “noise” from a power supply, such the computer to which it is connected, can travel along the USB cable connecting it. Connecting to your device via Bluetooth removes that source of noise.
  3. When measuring DC voltages with power supplies, some power supplies do not provide a steady DC signal. If the sensor voltage is fluctuating, try DC source such as a battery. If the sensor reading is correct, the problem may be the power supply.
  4. Is the output appropriate? The differential input range is 20 V. Over-voltage protection is provided so that slightly higher voltages will not damage the sensor.

You should NEVER use high voltages or household AC with these probes.

Additional Troubleshooting

• The readings from my Current and/or Voltage Probe are erratic, but if I measure the voltage with a multimeter instead, I get a solid reading. What is wrong with my sensor?
• What is the difference between a Differential Voltage Probe (DVP-BTA) or Go Direct Voltage Probe (GDX-VOLT) and the simple Voltage Probe (VP-BTA)?
• What is the overvoltage protection on the Differential Voltage Probe and Current Probe?
• What is the accuracy of a DVP-BTA voltage probe?
• How do I measure voltages larger than 6 (or 10) volts?
• How do I measure currents larger than 0.6 amperes?
• Is it possible to use the Voltage Probe (VP-BTA) when doing an Ohm's Law experiment, or is the Differential Voltage Probe (DVP-BTA) or Go Direct Voltage Probe (GDX-VOLT) required?
• An experiment using the current sensor of the power amplifier (PAMP) gives unexpected results

Specifications

• Differential input voltage range: 20 V
• Maximum voltage on any input: 24 V
• Input Impedance (to ground): 10 MΩ
• Differential Impedance: >20 MΩ
• Linearity: 0.01%
• Typical resolution: 5 mV (on Potential – 20 V channel)
• Supply current (typical): 9 mA
• Maximum Sampling Rate: 1,000 samples/s (USB or BLE)
• Connections:
  ⚬ Wireless: Bluetooth^® v4.2 (wireless range 30 m unobstructed)
  ⚬ Wired: USB 2.0 full speed
• Battery: 300 mA Li-Poly
  ⚬ Battery Life (single, full charge): ~24 hours continuous data collection
  ⚬ Battery Life (lifetime): 2 – 5 years (typical)

Calibration

Calibrate? No. The sensor is set to the stored calibration before shipping. If you wish to calibrate the sensor, you can conduct a two-point calibration. For more information, see How do I calibrate my sensor?

You may also zero the sensor before collecting data as an alternative to calibration. This is done by shorting out the leads of the sensor, then choosing the Zero option in the data-collection software. This option adjusts the calibration offset (intercept) but does not adjust the calibration gain (slope).

Battery Troubleshooting

1. If the sensor can be turned on when connected by USB but not when disconnected from USB, the battery either needs charging or has reached its end of life and can no longer hold a charge.
   ⚬ First, try charging the sensor for several hours.
2. If the sensor still won’t turn on when disconnected from USB, try swapping the battery with a working sensor to see if the problem follows the battery or stays with the sensor.
   ⚬ If the problem stays with the sensor, the battery is probably not the issue.
   ⚬ If the problem follows the battery, the battery has likely reached its end of life.
3. If you intend to use this sensor wirelessly, its battery will need replacing.
   Go Direct® 300 mAh Replacement Battery (GDX-BAT-300)
4. See How do I remove or replace a Go Direct battery? for more information (including a video).

Rechargeable batteries are covered by a one-year warranty.
Batteries should last two to five years in typical use.