Question

Color test of water is done with an instrument called

• A. Colorimeter
• B. Turbidimeter
• C. Tintometer
• D. Nephlometer

Hint:

Do not confuse color with turbidity—color is measured by tintometer, turbidity by nephlometer.

Answer 1

The Correct Option is C

Colour and turbidity are two different water-quality parameters, so the instrument has to match the parameter being tested. A turbidimeter and a nephlometer both work by detecting light scattered by suspended particles, which is a measure of cloudiness, not colour. A colorimeter measures how strongly a solution absorbs a chosen wavelength of light, which is closer to measuring concentration in a chemical assay than to grading the natural colour of a water sample. The instrument that is actually built around comparing a water sample's colour with a set of standard coloured references is the tintometer, and its very name reflects that purpose.

Therefore, the correct answer is Tintometer.

Answer 2

Breaking the instrument name down gives a strong hint here: "tint" refers to shade or colour, and this word origin lines up directly with what the question is asking about.

1. Colorimeter: Despite the name suggesting colour, this device is generally used to determine the concentration of a substance in solution by measuring light absorbance, not to grade the visual colour of water.
2. Turbidimeter: Its role is limited to quantifying turbidity from suspended solids, which has nothing to do with the true colour of the water.
3. Tintometer: Built specifically to compare a sample's colour against calibrated colour discs, this instrument directly performs the colour test described in the question.
4. Nephlometer: Like the turbidimeter, this measures scattered light from particles, addressing turbidity rather than colour.

Matching the instrument's purpose to the parameter in the question leaves the tintometer as the only instrument actually designed for colour testing.

Therefore, the correct answer is Tintometer.