Vernier Go Direct GDX-NH4 User Manual

1

Bluetooth®LED will blink red.

5. Launch Graphical Analysis 4.

6. Click or tap Sensor Data
Collection.

7. Click or tap your Go Direct sensor
from the list of Discovered
Wireless Devices. Your sensor's ID
is located near the barcode on the
sensor. The Bluetooth LED will
blink green when it is successfully
connected.

8. Click or tap Done to enter data­collection mode.

9. For best results, perform a two­point calibration using the High
and Low Standard solutions.

4. Launch Graphical Analysis 4 or turn
on LabQuest 2.

5. For best results, perform a two-point
calibration using the High and Low
Standard solutions.

Charging the Sensor

Connect the Go Direct Ammonium Ion-Selective Electrode to the included
Micro USB Cable and any USB device for two hours. Connecting the Go Direct
AmmoniumElectrode BNC to the amplifier during charging is optional.

You can also charge up to eight Go Direct Ammonium Ion-Selective Electrodes
using our Go Direct Charge Station, sold separately (order code: GDX-CRG).
An LED on each Go Direct Ammonium Ion-Selective Electrode indicates
charging status.

Charging

Blue LED on steady while sensor is connected to
the Micro USB Cable or Charge Station.

Fully charged

Blue LED is off when charging is complete.

Go Direct

®

Ammonium Ion­Selective Electrode

(Order Code GDX-NH4)

Go Direct Ammonium Ion-Selective Electrode (ISE) is used to measure the
concentration of ammonium (NH

4

+

) ions in aqueous samples.

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

l Go Direct Ammonium Ion-Selective Electrode (Go Direct Ion-Selective

Electrode Amplifier connected to a Go Direct Ammonium Ion-Selective
Electrode BNC Electrode)

l 30 mL bottle of High Standard solution with SDS (100 mg/L NH

4

+

-N)

l 30 mL bottle of Low Standard solution with SDS (1 mg/L NH

4

+

-N)

l Short-Term ISE Soaking Bottle
l Micro USBCable

Compatible Software

See www.vernier.co m/manuals/gd x-n h4 for a list of software compatible with the
Go Direct Ammonium Ion-Selective Electrode.

Getting Started

Please see the following link for platform-specific connection information:

www.vernier.com/start/gdx-n h4

Bluetooth Connection USB Connection

1. Install Graphical Analysis 4 on
your computer, Chromebook™, or
mobile device. See
www.vernier.com/ga4 for software
availability.

2. Charge your sensor for at least
2hours before first use.

3. Prepare the electrode by soaking it
in the High Standard solution for
30 minutes. Refer to the Using the
Product section for more
information.

4. Turn on your sensor by pressing
the power button once. The

1. Prepare the electrode by soaking it
in the High Standard solution for
30minutes. Refer to the Using the
Product section for more
information.

2. Install Graphical Analysis 4 on your
computer or Chromebook. If using
LabQuest 2, make sure LabQuest
App is up to date. See
www.vernier.com/ga4 for software
availability or
www.vernier.com/downloads to
update LabQuest App.

3. Connect the sensor to the USB port.

2

7. Slide the cap onto the electrode body, and then screw the cap onto the
storage bottle so the tip of the electrode is not touching the sponge.

Important: Do not fully submerge the sensor. The BNC connection is not
waterproof.

Important: Do not leave the ISE soaking for more than 24 hours.

Note: If the ISE needs to be transported to the field during the soaking process,

use the Short-Term ISE Soaking Bottle. Remove the cap from the bottle and fill
it 3/4 full with High Standard. Slide the bottle’s cap onto the ISE, insert it into
the bottle, and tighten it. For long-term storage, greater than 24 hours, make sure
the sensor is stored in its storage bottle with the sponge slightly damp.

Channels

Go Direct Ammonium Ion-Selective Electrode has six sensor channels. The
channel names are

l Potential (mV)
l Chloride (mg/L)
l Ammonium (mg/L)
l Calcium (mg/L)
l Nitrate (mg/L)
l Potassium (mg/L)

Note: The Ammonium channel is the default channel for this sensor. All
channels are mutually exclusive except Potential (i.e., You can display one
concentration channel and Potential at the same time, but you cannot display
two concentration channels at the same time). In order to collect data from the
other concentration channels, you must also attach the applicable corresponding
BNCelectrode to the amplifier.

Calibrating the Sensor

A calibration is stored on each sensor before it is shipped. As the membrane
ages, this factory calibration may become inadequate. For best results, we
recommend performing a two-point calibration.

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-n h4

Connected and charging Blue and Green LED solid when sensor is con-

nected to Graphical Analysis via USB and unit
is charging. (Green LED is obscured by the blue
one.)

Connected, fully charged Green LED 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.

Identifying the Sensor

When two or more sensors are connected, the sensors can be identified by
tapping or clicking Identify in Sensor Information.

Using the Product

1. Remove the storage bottle from the electrode by unscrewing the lid and
removing the bottle and lid.

2. Thoroughly rinse the lower section of the probe using distilled or deionized
water.

3. Soak the tip of the electrode for 30 minutes in the High Standard solution.

l The ISE should not rest on the bottom of the container.
l The small white reference contacts near the tip of the electrode should be

immersed.

l Make sure no air bubbles are trapped below the ISE.

4. Connect the sensor following the steps in the Getting Started section.

5. For best results, perform a two-point calibration using the High and Low
Standard solutions. For calibration instructions, see www.vernier.com/til/4011

6. When you are finished making measurements, rinse the electrode with
distilled water.