• pH Electrode
• Electrode Amplifier connected via BNC
• Electrode Storage Bottle, containing pH 4/KCl solution

Choose a platform below to see its compatibility requirements. This sensor requires an interface (sold separately).

LabQuest

Interface	LabQuest App
LabQuest 3	Full support
LabQuest 2 (discontinued)	Full support
LabQuest (discontinued)	Full support

Computers

	Software
Interface	Graphical Analysis	Logger Pro	Logger Lite
LabQuest Mini	Full support	Full support	Full support
LabQuest 3	Full support	Full support	Incompatible
LabQuest 2 (discontinued)	Full support	Full support	Full support
LabQuest Stream (discontinued)	Full support 1	Full support	Full support 1
Go!Link	Full support	Full support	Full support
LabQuest (discontinued)	Full support	Full support	Full support
LabPro (discontinued)	Incompatible	Full support	Full support

Compatibility Notes

1. Connect LabQuest Stream via USB. Wireless connection is not supported.

Chromebook

	Software
Interface	Graphical Analysis
LabQuest Mini	Full support
LabQuest 3	Full support
LabQuest 2 (discontinued)	Full support
LabQuest Stream (discontinued)	Full support 1
Go!Link	Full support
LabQuest (discontinued)	Full support

Compatibility Notes

1. Connect LabQuest Stream via USB. Wireless connection is not supported.

iOS

	Software
Interface	Graphical Analysis	Graphical Analysis GW
LabQuest Stream (discontinued)	Full support	Incompatible
LabQuest 3	Full support 1	Full support 1
LabQuest 2 (discontinued)	Full support 1	Full support 1

Compatibility Notes

1. iOS and Android^™ devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.

Android

	Software
Interface	Graphical Analysis	Graphical Analysis GW
LabQuest Stream (discontinued)	Full support	Incompatible
LabQuest 3	Full support 1	Full support 1
LabQuest 2 (discontinued)	Full support 1	Full support 1

Compatibility Notes

1. iOS and Android^™ devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.

Arduino

	Software
Interface	Arduino
Vernier Arduino® Interface Shield	Full support

LabVIEW

	Software
Interface	NI LabVIEW
SensorDAQ (discontinued)	Full support
Vernier myDAQ Adapter	Full support 1
Go!Link	Full support
LabQuest Mini	Full support
LabQuest Stream (discontinued)	Full support
LabQuest 3	Full support
LabQuest 2 (discontinued)	Full support
LabQuest (discontinued)	Full support

Compatibility Notes

1. You can only read the raw count/raw voltage output by this sensor. You must do the programming to convert to proper sensor units.

Texas Instruments

	Software
Interface	EasyData	DataMate	TI-84 SmartView	DataQuest	TI-Nspire Software
EasyLink	Full support 1	Incompatible	Full support 2	Full support	Full support 2
CBL 2 (discontinued)	Full support 3	Full support 3 4	Incompatible	Incompatible	Incompatible
LabPro (discontinued)	Full support 3	Full support 3 4	Incompatible	Incompatible	Incompatible
TI-Nspire Lab Cradle (discontinued)	Incompatible	Incompatible	Incompatible	Full support	Full support

Compatibility Notes

1. Use with TI-84 Plus calculators only.
2. Requires an Easy to Go! adapter
3. CBL 2 and LabPro interfaces cannot be used with TI-84 Plus CE calculators.
4. DataMate cannot be used with color screen TI-84 Plus calculators; use EasyData with these calculators.

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, especially around the bulb‑shaped tip, using distilled or deionized water.
3. Connect the sensor following the steps in the Getting Started section of this user manual.
4. When you are finished making measurements, rinse the electrode with distilled water.
5. Slide the cap onto the electrode body and then screw the cap onto the storage bottle so the tip of the electrode is immersed in the storage solution.

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

Do not leave the electrode in acids or bases with concentrations greater than 1.0 M for periods longer than 5 minutes. See www.vernier.com/ph-sensors for other types of pH electrodes.

For many experiments, calibrating the Tris-Compatible Flat pH Sensor is not required. A calibration equation is stored on each Tris-Compatible Flat pH Sensor before it is shipped, which is used as a default by Vernier software.

For the most accurate measurements with this sensor, we recommend calibration. It is a simple process that takes only a few minutes.

• For instructions for Tris-Compatible Flat pH Sensor calibration using Logger Pro computer software, see www.vernier.com/til/2341
• For instructions for Tris-Compatible Flat pH Sensor calibration using LabQuest App, see www.vernier.com/til/3394
• For instructions for Tris-Compatible Flat pH Sensor calibration using Graphical Analysis with a Chromebook, see www.vernier.com/til/3631
• For instructions for Tris-Compatible Flat pH Sensor calibration using Graphical Analysis with an iOS or Android device, see www.vernier.com/til/3630

In order to calibrate a Tris-Compatible Flat pH Sensor 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

Type	Double-junction, sealed, gel-filled, polycarbonate body, Ag/AgCl
Temperature range	5 to 80°C (readings not compensated)
Range	pH 0–14
Accuracy	± 0.2 pH units
Isopotential pH	pH 7 (point at which temperature has no effect)
Default calibration values	slope: –7.78 intercept: 16.34
Shaft diameter	12 mm OD
Membrane style	Flat glass
Cable	1 meter coaxial cable with BNC connector

Short-term storage (up to 24 hours): Place the electrode in pH 4 or pH 7 buffer solution. It should never be stored in distilled water.

Long-term storage (more than 24 hours): Store the electrode in a pH 4 buffer/KCl storage solution in the storage bottle. The pH electrode is shipped in this solution. Vernier sells 500 mL bottles of pH Storage Solution (order code PH‑SS), or you can prepare additional storage solution by adding 10 g of solid potassium chloride (KCl) to 100 mL of pH 4 buffer solution. Vernier sells a pH Buffer Capsule kit (PH-BUFCAP) that includes a buffer solution preservative. Storing the electrode in this solution contributes to electrode longevity and retains electrode response time when the unit is placed back into service.

If the electrode is inadvertently stored dry for a short period of time, immerse the tip in the pH 4 buffer/KCl storage solution for a minimum of 8 hours prior to use. If the readings are still not accurate after calibration or if the response is slow, try shocking the sensor as described in the Troubleshooting section.

The Tris-Compatible Flat pH Sensor is a sealed, gel-filled, double-junction pH Electrode attached via BNC to our Electrode Amplifier. The double-junction pH Electrode prevents silver from the Ag/AgCl gel from coming in contact with the sample. Tris buffers (tris(hydroxymethyl)aminomethane) and solutions with proteins and sulfides will react with silver to clog the reference junction, shortening the life of single-junction electrodes.

The measurement electrode is made of flat glass, making it more durable and easier to clean than a traditional glass bulb. In addition to liquids, it is ideal for measuring the pH of semisolids such as many foods and soil slurries. It also allows for flat surface measurements and the use of smaller sample sizes.

The Electrode Amplifier that is included with the sensor amplifies the electrode’s mV reading into the appropriate range for the interface. It also provides the software with the calibration values that convert the voltage into a pH value.

When testing a Tris-Compatible Flat pH Sensor, it is best to measure a buffer solution because it is easier to determine if the sensor is reading correctly. Do not test your sensor by measuring distilled water. Distilled water can have a pH reading in the range of 5.5–7.0, due to varying amounts of dissolved carbon dioxide. Furthermore, due to a lack of ions, the pH values reported with the sensor in distilled water will be erratic.

If your Tris-Compatible Flat pH Sensor is reading differently from the pH of a buffer solution (e.g., reads 6.7 in a buffer 7), you may simply need to calibrate the sensor. See the Calibration section for more information.

If your readings are off by several pH values, the pH readings do not change when moved from one buffer solution to a buffer solution of different pH, the sensor was stored dry for an extended period of time, or the sensor’s response seems slow, the problem may be more serious. A method called “shocking” can be used to revive pH electrodes. To shock your pH Sensor, perform the following:

1. Soak the pH Electrode for 4–8 hours in an HCl solution of 0.1 M–0.5 M.
2. Rinse off the electrode and soak the tip in freshly prepared long‑term storage solution (recipe above) for 30–60 minutes.
3. Rinse the electrode and test it with buffer solutions of known pH.

Occasionally, mold will grow in the pH 4 buffer/storage solution. Mold will not harm the electrode and can easily be removed using a mild detergent solution. Mold growth in the storage solution can be inhibited by adding a buffer preservative.

For additional troubleshooting and FAQs, see www.vernier.com/til/1361

If you have followed the troubleshooting steps and are still having trouble with your Tris-Compatible Flat pH Sensor, 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.

Item	Order Code
pH Storage Solution, 500 mL	PH-SS
pH Buffer Capsules (3×10) Kit	PH-BUFCAP
Storage Solution Bottles, pkg of 5	BTL

Vernier warrants this product to be free from defects in materials and workmanship for a period of five years from the date of shipment to the customer. This warranty does not cover damage to the product caused by abuse or improper use. This warranty covers educational institutions only.