Ultraviolet Transmittance (UVT%) measures how much UV light at 254 nm passes through 1 cm of water. To measure it we use a spectrophotometer. For best results you will need the spectrophotometer (we recommend using a portable one), Quartz cuvettes, and reference water (can be distilled water).
1. Prepare the Spectrophotometer
Turn on the spectrophotometer and allow it to warm up according to the manufacturer’s instructions.
Set the wavelength to 254 nm, which is the standard for UVT measurement.
If you are using a mobile spectrophotometer, it is already set to 254 nm.
2. Calibrate the Instrument
Use a clean cuvette filled with deionized or ultrapure water as the reference (blank).
Insert the blank into the spectrophotometer and set the instrument to 100% transmittance (or 0 absorbance).
This establishes the baseline for your measurements.
3. Collect the Sample
Obtain a water sample representative of the system you are analyzing.
4. Prepare the Sample
Rinse a clean cuvette thoroughly with the water sample.
Fill the cuvette with the sample, ensuring no air bubbles are trapped inside, as they can affect readings.
Wipe the outside of the cuvette with a lint-free cloth to remove fingerprints or smudges.
5. Measure the Sample
Insert the sample cuvette into the spectrophotometer.
Record the transmittance value displayed on the spectrophotometer.
6. Document the Results
Note the UVT percentage and any relevant conditions (e.g., temperature, time, sample source).
Perform multiple measurements to ensure consistency and reliability.
7. Rinse the Cuvette with the Reference Water, Clean and Dry
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