Ammonium Ion-Selective Electrode

The Go Direct Ammonium Ion-Selective Electrode (ISE) can be used to measure the concentration of ammonium (NH4+) in aqueous samples. It connects via Bluetooth® wireless technology or via USB to your device.


Use the Go Direct Ammonium Ion-Selective Electrode to wirelessly measure levels of ammonium ions introduced from fertilizers. It can also indicate aqueous ammonia levels, if sample solutions are acidified to convert NH3 to NH4+.

The versatile BNC connector allows students to easily replace the electrode when it expires or becomes damaged. You need only replace the electrode and not the entire sensor—lowering your overall equipment costs.

The Go Direct Ammonium Ion-Selective Electrode has a combination-style, non-refillable, gel-filled electrode. Like all other PVC ISE membranes, the membrane on the ISE has a limited life expectancy. However, the replaceable module of ISE allows you to simply discard the used membrane module and replace it with a new one.

Rechargeable Battery—Ready When You Are

The robust rechargeable battery offers long battery life and provides always-ready operation when using the sensor wirelessly. Monitor battery life directly from our free Graphical Analysis 4 app or LabQuest 2 App. Should the battery run low, simply connect the sensor to the charging cable and keep on collecting—no interruptions or inconvenience to you or your students.

Wired or Wireless—The Flexibility to Choose

Our Go Direct sensors connect directly to your mobile device, Chromebook, or computer using our free Graphical Analysis 4 app—no additional equipment or software purchases are necessary. Go Direct sensors can be used wired via USB or wirelessly via Bluetooth® wireless technology, allowing you to choose the solution best for your classroom or laboratory.

Note: We recommend that you do not purchase ISE replacement modules too far in advance of their expected time of use as degradation occurs while they are stored on the shelf.

Important: Ion-Selective Electrodes require good chemical technique and careful calibration to obtain accurate results; they are not recommended for middle school or elementary students.


  • Range (mV): ±1000 mV
  • Range (concentration): 1 to 18,000 mg/L (or ppm)
  • Accuracy: ±10% of full scale (calibrated 1 to 100 mg/L)
  • Interfering ions: K+, Li+, Na+, Cs+, Mg2+, Ca2+, Sr2+, Ba2+
  • pH range: 2–7 (no pH compensation)
  • Temperature range: 0–40°C (no temperature compensation)
  • Electrode slope: 55 ±3 mV/decade at 25°C
  • Electrode resistance: 0.1 to 5 MΩ
  • Minimum sample size: must be submerged 2.8 cm (1.1 in)
  • Connections:
    • Wireless: Bluetooth
    • Wired: USB

What’s Included

  • Go Direct ISE Amplifier attached to a Go Direct Ammonium Ion-Selective Electrode BNC
  • Micro USB cable
  • 30 mL bottle of High Standard solution with SDS (100 mg/L NH4+ as N)
  • 30 mL bottle of Low Standard solution with SDS (1 mg/L NH4+ as N)
  • Short-Term ISE Soaking Bottle