Trans Instruments (S) Pte Ltd

5 Jalan Kilang Barat #06-04/05 Petro Centre 159349 Singapore ,

The Science Of Water

There is a well-established technology of water. There is a science of water and engineers have worked with water throughout recorded history. But there are always new problems and new ways of working with water to meet new uses and new developments in technology. This is what makes mere simple water so interesting.

New water treatment technology has established the point-of-use (POU) application. The most generally used systems were the distiller system, Reverse Osmosis (RO) system and carbon block filtration. The most recent development is the alkaline water system, also known as magnetized water. As such, the standard of drinking water has been raised to a higher level. This allows vast variety of application from household drinking water to medical and industrial application.

Water Facts

Water is in liquid form between 0º to 100ºC (32º to 212ºF)
Water is in solid at or below 0ºC (32ºF)
Earth's rate of rainfall is approximated at 340 cubic mile per day (16 million tons per seconds)

Unit of measurement

  • 1 gallon s = 8.33 pounds = 3.778 kilograms
  • 1 gallons = 3.785 liters
  • 1 cubic foot = 7.5 gallons = 28.35 liters
  • 1 ton = 240 gallons
  • 1 acre foot = 43,560 cubic feet = 325,900 gallons

Drinking Water Standards

Below are just some drinking water quality standards, with reference from the US public health service or the world health organization.

Aluminum 0.1ppm Manganese 0.1ppm
Ammonia 35ppm Chloride 250ppm
Alkalinity 1.5ppm Chlorine 5ppm
Copper 1ppm Sulfate 250ppm
Calcium 200ppm Detergents (ABS) 0.5ppm
Magnesium 150.3ppm Total Dissolved Solids (TDS) 500ppm
Iron 0.3ppm pH 7.0 to 9.0pH

Visit the WHO web site at for full detail explanation on acceptability of drinking water.
Of all the above parameters, the most general and basic measurement for drinking water is pH and TDS.


pH is a unit of measure that describes the degree of acidity or alkalinity of a solution. It is measure on a scale of 0 to 14. Technically, pH is defined as the negative logarithms of the hydrogen ion activity or concentration.

pH = -log[H+]

The value of pH 7.0 represents neutrality. Below pH 7.0 is acidic and above 7.0 is alkaline. The easiest way to measure pH is using the Trans Senz pH tester. A more professional range of pH meter like and  WalkLAB microprocessor pH meter for field testing and the Benchtop pH meter BP3001 are more suitable for industrial and medical application.


TDS (Total Dissolved Solid) is the measure of the total solid dissolved in water. The unit of measurement is express as ppm (parts-per-million) or 1 milligram of solid dissolved in 1 liters of distilled water.

The method to acquire TDS reading is by the conversion of conductivity units. Conductivity is the ability of a material to conduct, that is allows electrical current to flow. Substances with high conductivity are copper, silver, metal in general. Substances with low conductivity are glass, ceramic, plastics and water (H20).

Pure Water is not conductive. It becomes conductive when there are ions present. Hence Conductivity meters are generally used to measure purity of water. Below are some references of types of water and their conductivity ranges and the product to use for measurement:

Type of Water's Conductivity and its Measuring Instrument

(ppm as NaCl)
Absolute pure water (H2O)
0.11 HC9021
Distilled water
De-mineralized water
Power Plant Boiler water
Pure Mountain stream water
Good City water
Cooling tower
up to 6500 
up to 13,000
Ocean water

Today's point-of-use systems are not maintenance free. To keep check on these systems, the best and most convenient way is to test the TDS or Conductivity measurement of the product water like the Trans Senz TDS are excellent tools to check the system. Industrial application and in hospitals can use the RO meter or the WalkLAB Conductivity Pro meter to take precise measurements.

Distillers and RO (reverse osmosis) systems are getting very popular. RO systems have a rejection of 90 to 98% of dissolved solid to produce clean water. A demo tool called the ELECTROLYZER-2I can be used to visually demonstrate between purified water against tape water before RO system.