Protocols below are for use with Pasco probes.

Materials:

PasPort Xplorer
PasPort colorimeter sensor
USB cable
DataStudio software
Cuvette (provided by Pasco)
Distilled water

Steps for calibrating the colorimeter:
1. Connect the colorimeter sensor to the Pasport Xplorer device.
2. Connect the PasPort Xplorer device to the computer with the USB cable.
3. Fill a cuvette with distilled water.
4. Insert this cuvette into the cuvette holder in the colorimeter and close the lid tightly, so that light cannot enter the casing.
5. Press the green "Calibration" button on the sensor. The light illuminates to indicate calibration is in progress.
6. Wait for the light to turn off. The colorimeter is now calibrated.
7. To verify, click the "Start" button in DataStudio. All color readings should approximate 100% transmittance.

Note: A blinking red light on the "Calibration" button means either (a): The dark count is too high; stray light is entering the cuvette holder or (b): The sensor measurement is out of range. The light turns off when the reading is within the normal range.