Vernier Software and Technology
Vernier Software & Technology
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How do I manually calibrate my sensor in Graphical Analysis 4 for iOS/Android?

In most cases it is not necessary to calibrate sensors; however, for optimum accuracy you may choose to calibrate them manually.

To perform any calibration, you will need one or more external references for your sensor. For example, to do a two-point calibration for a pH sensor you will need two pH buffer solutions. Your calibration is only as good as your knowledge of the reference values. Note: For best results, the two calibration points should be widely separated and be on either side of the intended readings you anticipate in your experiment.

Depending on the sensor attached, you may have the option of a one-point, two-point, or three-point calibration.

Performing a Two-Point Calibration with a LabQuest (wired) Sensor
1. Connect the sensor according to the Getting Started section of the product's user manual (See https://www.vernier.com/support/manuals/).
2. Click the live readouts meter and choose Calibrate.
3. Place the sensor in the first known set of conditions (e.g., known suspended mass or known pH buffer). If using a wet sensor, remove the storage bottle from the sensor (if applicable), rinse the tip of the sensor with distilled water, and place the sensor in the first standard solution so the tip is immersed. Note: If you wish to initiate a one-point calibration, make sure the toggle switch is set to green next to One-point calibration.
4. Type in the first known calibration value in the edit box. When the voltage reading stabilizes, click Keep. If you are performing a one-point calibration, click Apply to complete the calibration process. If performing a two-point calibration, continue to Step 6.
6. Move the sensor to the second set of known conditions. If using a wet sensor, rinse the sensor with distilled water and place it in the second standard solution. The potential (voltage) will change.
7. Enter the second known calibration value in the edit box. When the voltage reading stabilizes, click Keep.
8. Tap Apply to complete the calibration process.

Performing a Two-Point Calibration with a Go Direct Sensor
1. Connect the sensor according to the Getting Started section of the product's user manual (See https://www.vernier.com/support/manuals/).
2. Click the live readouts meter and choose Calibrate.
3. Select the type of calibration you would like to perform (e.g., One-point, Two-point, etc.).
4. Place the sensor in the first known set of conditions (e.g., known suspended mass or known pH buffer). If using a wet sensor, remove the storage bottle from the sensor (if applicable), rinse the tip of the sensor with distilled water, and place the sensor in the first standard solution so the tip is immersed.
5. Type in the first known calibration value in the edit box. Tap Return. When the relative stability reading stabilizes, click Keep. If you are performing a one-point calibration, click Apply to complete the calibration process. If performing a two-point calibration, continue to Step 6.
6. Move the sensor to the second set of known conditions. If using a wet sensor, rinse the sensor with distilled water and place it in the second standard solution.
7. Enter the second known calibration value in the edit box. Tap Return. When the Relative Stability Reference reading stabilizes, tap Keep.
8. Tap Apply to complete the calibration process.

Storing the Calibration to the Sensor
With Go Direct Sensors, the calibration is stored to the sensor automatically.
With Standard Sensors, calibration storage has not yet been implemented. You can view the calibration equation in the calibration screen. Record this value and type it in next time you plug in the sensor to bypass the calibration process.

Related TILs:
Calibration in other platforms:
TIL 3394: How do I manually calibrate my sensor in LabQuest?
TIL 3395: How do I manually calibrate my Go Wireless pH or EA in Graphical Analysis GW for iPad or Android?
TIL 2341: How do I calibrate a sensor in Logger Pro?
TIL 2342: How do I store the calibration for my sensor using Logger Pro?

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