Device Hardness Tester Or TDS It is a device for measuring the sum of soluble particles in liquids that represent salt ions in water. TDS stands for Total Dissolved Solid, which means the total concentration of all ions in water that can be measured by hardness meters. The unit of measurement of TDS hardness is milligrams per liter Mg / l, which is also called PPM (part per thousand). Hardness by Hardness Tester High accuracy is a matter of concern.
Overall hardness indicates the amount of magnesium and calcium ions dissolved in water. In fact, general hardness is a means of measuring metal ions such as calcium, magnesium and zinc, which are formed by the passage of rainwater through rocks.
Most waters contain a combination of calcium, magnesium, salt, and small amounts of other metals that need to be handled to prevent dissolved ions from rising. First, temporary hardness is formed in water and with the entry of carbonate into water, general hardness is formed.
Maximum allowable amount TDS Drinking water is listed in the drinking water standard. This amount is mentioned in the standard of Iranian drinking water 1500 and in special conditions 2000 mg / liter.
Due to the fact that alkalinity, acidity and hardness of solution are directly related and increasing one of them increases the other two, many measuring devices have the ability to measure several parameters and can often alkalinity, acidity. Measure chloride, total hardness, oxygen, chlorine, ammonia, phosphate, hydrazine.
These types of devices are divided into two groups in terms of measurement method:
1- Volumetric kits The
most common and most accurate measurement method for Measurement of ion concentration In water, there are volumetric kits. In this method, a small cylinder and containers equipped with a dropper are used. The cylinder is filled to the mark line of the sample, and the necessary reagents are added to it. Drops of standard solution are added to the sample. When all the desired ions react with the standard solution, the sample will change color. This is known as the end point. The number of droplets consumed from the standard solution multiplied by a certain coefficient will determine the desired ion concentration.
2- Colorimetric kits
By this type of kit, the desired ion concentration is measured through colorimetric. A certain amount of chemical reagents are added to the sample, these reagents react with the desired ion and produce a specific color, the ion concentration is determined by comparing the intensity of the color created with the color sample of the test container.