How TDS meters work (The Ultimate Guide)

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Written By John Roe Stephen

Taking a reading from a TDS meter is a simple process that may consume from one minute to a few minutes. That is why A TDS meter is a crucial household device. But, its process is not a similar one.

Although you don’t have to know everything about it, knowing how it works will help you to get readings more accurately and use the device ideally.

What is TDS?

Total Dissolved Solids is a reading about a solution or a concentration at a given time. It delivers the amount of organic, inorganic, or any other solid availability in the given solution.

Although the liquids are targeted through the TDS reading, molecular, ionized, or micro-granular suspended form is also delivered as TDS value.

TDS is delivered as parts per million. For example, if the reading taken from a sample is 45, it means there are 45 parts per million in the solution.

What is TDS in water?

It means the number of solids in water, which has been counted as parts per million. That includes the minerals or any other particle that may have dissolved in water. Certain TDS ranges are declared according to the quality of the water.

According to the TDS value found in water, it is possible to assume the levels of minerals, salts, metals, and other impurities are in the water.

How do TDS meters work?

The basic theory behind TDS meter operation is electrical conductivity. After the meter is placed in a sample of water or any solution, an electrical current will be passed through the water. The TSD value is generated according to the quality of the conductivity experienced by the TDS meter.

If the concentration of dissolved solids or any impurities is higher in the water, the electric conductivity will be higher in the water. Other factors may change the TDs value, such as the temperature, electronic fields in the surrounding, and the TDs meter’s quality.

What Are the Common Issues That Could Cause a Zero Water TDS Meter to Stop Working?

A zero water tds meter comprehensive solution is vital. Common issues causing it to stop working include battery problems, faulty sensors, or calibration errors. Ensure the battery is functional, and the sensors are clean and dry. Perform regular calibration checks and follow manufacturer guidelines for accurate readings and continued functionality.

What is a TDS meter made of?

A TDS meter is a combination of several electrical parts.


The sensor of the TDS meter measures the electrical conductivity of the water.  It is proportional to the total dissolved solids (TDS) content. The conductivity and capacitance sensors are two types of sensors used in TDS monitoring.

Circuit Board

The circuit board is made of electronics. It involves taking the readings from the sensor and displaying the TDS level on the meter. Since this is the most important part of the TDS display, you must not wet this while taking the readings.


The display of a TDS meter comes in many forms. There are manual and digital TDS displays. Most TDS meters come with an LCD display that shows the TDS reading in parts per million (ppm). We discovered that some TDS displays come as graphical displays.


The housing of the TDS meter protects the internal circuits from damage.  It also makes the meter easier to handle. Plastic housings are used for more than 85% of TDS meters.

Power Source

TDS meters typically require LR44 alkaline batteries as the power source. Some models may also require an AC adapter option. Most TDS meter models provide the power source as a component. There is a battery cap that the users need to remove first.

Note: The parts we described in the article are parts of a handheld digital TDs meter which is the most common TDS meter type. There can be more additions in other TDS meter types.


A TDS meter’s functioning is always a simple one. Although how it processes its data or how it functions is not your concern, you must manage to do basic maintenance practices. Only after that will you never have to bother with “How Do TDS meters work.”

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