Suspended Solids Analyzer | TSS monitor | Suspended Solids Meter (2023)




How do you measure from low NTU to 8% solids? Using SoliSense®from Pi. Using patented optical technology, Pi's easy-to-use, low-drift, self-cleaning HEPA sensor is a cost-effective way to measure suspended solids in a variety of applications, including all applications associated with municipal sewer systems and municipal water systems, such as suspended water mix plants (MLSS), return sludge (RAS), plant inlet and outlet, concentrate, filter backwash, and other monitoring needs. Because of its patented technology that allows you to measure such a large area on a single sensor, SoliSense®it has built-in self-cleaning for long service intervals with only a once-a-year calibration check. Installation can be by immersion in a tank or insertion into a pipe.

SoliSenseGenericName®HEPA meter 3D view


  • 2 NTU at 8% solids
  • Displays in NTU, mg/l, g/l or % solids –flexible
  • AutoClean optical sensor –months without maintenance
  • Stable and reliable-excellent process control
  • Suitable for all drinking, waste and process water
  • Up to 12 months between maintenance
  • Up to 12 months between calibration

The patented technology in SoliSense®means that a single sensor can cover a very large area. This means you don't need as many different sensors in a water treatment plant (WTW) or sewage treatment plant (WWTW). This in turn means;

  • Fewer spare parts –must be held in one or more investments
  • No need to know range before ordering -easier shopping
  • An online suspended solids analyzer can be:
    • MLSS-Meter
    • TSS-Meter
    • Total counter of suspended subjects online
    • Online wastewater monitoring
    • Online admission monitoring
    • Online analyzer for suspended solids in the process

The SoliSense®is designed to meet all suspended solids monitoring applications in water treatment plants and wastewater treatment plants, including:

  • admission surveillance(Turbid 2-4,000 NTU)
  • wastewater monitoring(suspended matter 0-1,000 mg/l)
  • Online suspended solids analyzer
  • On-line-RAS-Meter(return activated slime)
  • Medidor MLSS on-line(mixed suspended liquid solids)
  • Contador WAS online(activated sludge waste)
  • Thickened Sludge–Total counter of suspended subjects online
  • centered–Total counter of suspended subjects online
  • filter-Total counter of suspended subjects online
  • backwash water -To control filter backwash in a water treatment plant
  • waste water waste water -Total counter of suspended subjects online
  • wastewater inlet -Total counter of suspended subjects online
(Video) Portable Suspended Solids Sensor Calibration

The SoliSense®The HEPA sensor can be supplied with several installation options including;

  • Dive -where the sensor is mounted on the end of a pole that submerges it in a tank or open body of water
  • Insert -It involves inserting the sensor into a tube through a special ball valve that allows the sensor to be removed while still under pressure.
  • flow cell -where the sensor is mounted in a special flow cell and the sample flows through it.

To learn more, scroll down and download the brochure or contact us to discuss the best option for your application.

Each sensor has an LED light source that emits in the infrared and has a useful life of 15 years. Each suspended matter sensor has two detectors.

The emitted light is detected by the emitter detector. This light then passes through the sapphire optical windows and enters the sample. By refraction and reflection, some light enters the sensor back into the detector, which is at an angle of 120 degrees to the emitted light, and the ratio of emitted light to received light is proportional to the suspended solids in the sample. By varying the amount of light emitted, the sensor can correct for effects caused, for example, by the optical properties of windows or aging optics or drifting electronics (fully electronic drift). This patented technology guarantees SoliSense's stability and range.®.

The electronics provide a fully scalable output that allows SoliSense to®to measure any part or all of the scale. The sensor probe is equipped with the ability to periodically sweep a stream of water across the optical lens to keep it clean. If you have an application ranging from low NTU to percent solids then SoliSense is for you®is certainly the suspended matter monitor for you! With up to 5 calibration points, you can accurately monitor your process over a wide range of sample concentrations.

The probes are constructed from 316 stainless steel with sapphire optical windows, allowing them to withstand demanding operating environments.

Using two detectors in a single probe it is possible to:

  • Measure turbidity from 2 NTU to 4,000 NTU
  • Measure solids from 0.001 to 80 g/l (8% solids) –lama
  • Measurement of solids from 0.001 to 500 g/l (50% solids) -silicates

Focus Ons are a series of short emailed articles providing technical information on instrumentation, process measurement in potable water, wastewater, process water and swimming pool. If you would like to be added to the mailing list, pleasecontact us.

>>SoliSense<sup>®</sup> for TSS monitoring

>>probe contamination

Total suspended matter measurement – ​​SoliSense®Article592kB
Measurement of suspended solidstechnical note742kB
SoliSense® for TSS monitoringtechnical note753kB
SoliSense® mounting optionstechnical note686 KB
probe contaminationtechnical note459kB

common questions

Suspended solids are particles suspended in water. They occur naturally and can be observed, for example, in rivers after a rain event when the river is “muddy”.

The treatment of water and effluents has two main focuses: the removal of organic matter and particles and, subsequently, disinfection. Information on suspended solids content can be invaluable for treatment processes (e.g. tracking changes in suspended solids in raw water entering a potable water facility or monitoring the effectiveness of effluent on exit) and therefore , these types of sensors are widely used in many industries and applications.

Suspended solids are usually measured in mg/l. When present in large amounts, a percentage or g/l is sometimes used.

Suspended matter and turbidity are measured differently but are related. Suspended solids measurements are based on the mass of solids present in a given volume of water (mg/L), while turbidity measures how "cloudy" it is in NTU. A common conversion is 1 mg/l = 2 NTU, but different suspended solids may have different proportions.

The qualities of the process water and solids to be measured influence the maximum value that can actually be measured. For a “clean” application (eg silica in clean water), we can expect to safely measure up to 50% solids (500,000 mg/l). At the other end of the spectrum, black sludge in a wastewater treatment plant may have a reliable threshold of only 5% (50,000 mg/L). Experience shows that in most wastewater treatment plants the upper limit is around 8% solids (80,000 mg/l).

The SoliSense®comes standard with built-in temperature compensation, so temperature changes have negligible effect on the sensor. However, SoliSense®it is a robust stainless steel sensor with considerable weight; With SoliSense, it can take some time®to reach thermal equilibrium, therefore rapid temperature changes (>2°C for 10 min) may affect the reading.

"The Pi products offer excellent value for money and represent the best municipal drinking water analyzers available."

John Clark


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Equip Solutions - Illinois, USA

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Link Automation - United States
(Video) How to Monitor Suspended Solids using Pi's Suspended Solids Meter - Measurements - SoliSense

“We've been using these analyzers since 2008. They are easy to use and very stable. Calibration and maintenance are quick and easy.”

Lloyd Gruginsky

Chehalis WTP - Chehalis, WA

“At Scottish Water, we have been using the excellent Pi LabSense 3 and handheld UV254 instruments in the field to optimize our water treatment processes for several years. We find them easy to use and invaluable in identifying and resolving issues in a timely, efficient and effective manner. Two great pieces of kit!”

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"Simply the best turbidity available."

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Jinan Hongquan Water Company - China
(Video) Total Suspended Solids (TSS) Demonstration

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Qingdao Guolin Environmental Technology Co., Ltd., - China

“Over the past few years, we've purchased Chemtrac chlorine and turbidity analyzers, and during routine calibration, the probes measure chlorine and turbidity with no issues. We are very satisfied with this product and highly recommend it.”

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Ocoee Utility District - Ocoee TN

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(Video) Testing result reading--Portable Suspended Solids Analyzer LH-XZ03

Suspended solids gauge downloads



(Video) Suspended Solids Sensor Span Calibration


How do you measure the concentration of suspended solids? ›

A water sample is filtered through a pre-weighed glass fiber filter, capturing the solids larger than 2 um. Then, the filter is dried in an oven to remove remaining water and weighed again. The weight difference over the sample volume provides the TSS concentration in mg/L.

What is the detection limit for TSS? ›

The determination of total suspended solids in chemical plant effluent. This method is limited to the determination of TSS in water samples collected from natural bodies of water containing TSS of < 20,000 mg/L. The desired detection limit for this method is 0.5 mg/L for a 1-L sample.

What does a TSS meter do? ›

The Instrument is ideal for remote monitoring in municipal and industrial wastewater, drinking water, and river monitoring. It can be used as an optimisation tool for monitoring processes or as an easy way to calibrate or validate online sensors.

What is the measurement for TSS and TDS? ›

TSS is measured by weighing the dried material on the filter. TDS is defined as the portion of organic and inorganic solids passing through the same filter (Rice et al.

How do you measure total solids? ›

Total solids are measured by weighing the amount of solids present in a known volume of sample. This is done by weighing a beaker, filling it with a known volume, evaporating the water in an oven and completely drying the residue, and then weighing the beaker with the residue.

What is used to measure suspended solids during testing? ›

You can accurately calculate total suspended solids in wastewater by using a TSS sensor or monitor. These devices measure water in the region of 1,000 mg/L – 8% solids, indicating the presence of suspended solids in water.

What is normal TSS values? ›

TSS is the most common measure of the amount of solids, both organic and inorganic, in wastewater effluent. Raw wastewater has a TSS typically ranging from 155 to 330 mg/L, with 250 mg/L being typical concentration. After going through primary treatment in a septic tank, a typical TSS value is less than 65 mg/L.

What is the minimum detection limit? ›

The method detection limit (MDL) is defined as the minimum measured concentration of a substance that can be reported with 99% confidence that the measured concentration is distinguishable from method blank results.

What is the limit for suspended solids? ›

Explanation: The maximum permissible limit for suspended solids is 30mg/l for testing waste water which is set by the Environmental Protection Agency (EPA).

What does a high TSS value mean? ›

High TSS in a water body can often mean higher concentrations of bacteria, nutrients, pesticides, and metals in the water. These pollutants may attach to sediment particles on the land and be carried into water bodies with storm water.

How do you calculate total dissolved solids? ›

Conductivity (EC) and total dissolved solids (TDS) are water quality parameters, which are used to describe salinity level. These two parameters are correlated and usually expressed by a simple equation: TDS = k EC (in 25 0C). The process of obtaining TDS from water sample is more complex than that of EC.

Are total solids the same as suspended solids? ›

What is the difference between Total Dissolved Solids and Suspended Solids? Total Dissolved Solids (TDS) describes to the solid particles that can pass through a 2-micron filter. The solids in a liquid that cannot pass through this filter, i.e. the larger particles, are described as suspended solids.

What is the measurement of suspended particles? ›

"Suspended particulate matter" is measured and characterised in various ways: Total Suspended Particles is the fraction sampled with high-volume samplers, approximately particle diameters <50-100 µm. PM10: Inhalable particles, diameter <10 µm.

What is maximum detection limit? ›

The limit of detection (LOD) is defined as the lowest concentration of an analyte in a sample that can be consistently detected with a stated probability (typically at 95% certainty) [24].

How do you handle measurements below the detection limit? ›

These concentrations are said to be below the limit of detection (LOD). In statistical analyses, these values are often censored and substituted with a constant value, such as half the LOD, the LOD divided by the square root of 2, or zero.

How do you measure limits of detection? ›

A traditional and typical approach to estimate LoD consists of measuring replicates, usually n=20, of a zero calibrator or blank sample, determining the mean value and SD, and calculating LoD as the mean +2 SD. Variations of this approach use the mean plus 3, 4, or even 10 SDs to provide a more conservative LoD.

What is a good TDS meter reading? ›

What is the best TDS level for drinking water? Ans: Generally, the TDS level between 50-150 is considered as the most suitable and acceptable.

What if TDS is less than 50? ›

TDS is made up of a variety of salts, minerals, and organic compounds, including Calcium, Chlorides, Sulfates, Magnesium, Potassium, Carbonates, and Bicarbonates, among others.
How Much TDS Level in Water Good For Health.
TDS Level (Milligram/Litre)Remarks
Less than 50Unacceptable as it lacks essential minerals
8 more rows

Does a high TDS level always mean the water is unfit for consumption? ›

In most instances, TDS in your drinking water will not present a health problem but it's important to note, should TDS levels exceed 1,000 mg/L, the drinking water can be considered unfit for human consumption.

What is used to measure concentration of suspended particles? ›

Measurement of the suspension concentration of separate particles, 'or clusters of particles can be done with a hydro- meter (Bouyoucos, 1936) or with the pipette method (Kilmer & Alexander, 1949).

How do you measure sediment concentration? ›

Grab samples

The sediment contained in a measured volume of water is filtered, dried and weighed. This gives a measure of the concentration of sediment and when combined with the rate of flow gives the rate of sediment discharge.

Which method of measuring concentration is used in solid mixtures? ›

Molarity (M):

One of the most commonly used methods for expressing the concentrations is molarity. It is the number of moles of solute dissolved in one litre of a solution.

What is the concentration of solid particles in suspension? ›

At suspension concentrations greater than about 3% (though this will depend on the source of the clay) the suspensions are non-settling. Dispersion of bentonite in water can take some time. On contact with water the particles swell and once sufficiently swollen the clusters of particles break up.

How do you measure total suspended particulates? ›

"Suspended particulate matter" is measured and characterised in various ways: Total Suspended Particles is the fraction sampled with high-volume samplers, approximately particle diameters <50-100 µm. PM10: Inhalable particles, diameter <10 µm.

What is the suspension method of measuring volume? ›

A little-known method of measuring the volume of small objects based on Archimedes' principle is described, which involves suspending an object in a water-filled container placed on electronic scales. The suspension technique is a variation on the hydrostatic weighing technique used for measuring volume.

What are the two common methods for measuring the concentration? ›

Concentration of a Solution

There are two basic ways of reporting the concentration of a solute in a solvent, by reporting the mass of solute in a given volume of solution, or the number of moles of solute in a given volume of solution.

How do you calculate total suspended sediment? ›

Determine total suspended-sediment discharge (in tons for the period of interest by multiplying the mean daily suspended-sediment discharge (from step h) by the total number of days in the period.

How do you measure sedimentation rate of suspension? ›

The sedimentation rate (SR) of non-aggregated spherical particles in suspension was determined using an ultrasonic interferometry technique (Echo-Cell); this method is based on A-mode echography and measures the rate of formation of a sediment on a solid plate during settling.

What can you use to measure sedimentation? ›

Optical Laser diffraction point sensors (LISST)

Various Optical Laser diffraction instruments (LISST) are commercially available to measure the particle size and concentration of suspended sediments.

What are 3 ways to measure the concentration of a solution? ›

The three ways to measure the concentration of a solution are molarity, mole fraction, and molality.
  • Molarity (M): It is calculated by the number of moles (n) of solute and volume of solution (V). ...
  • Mole fraction (x): It is the ratio of number of moles of particular element ( ) and total number of moles of substance ( ).

What is the most accurate way to measure concentration? ›

In science we want a more accurate method to measure concentration, so we use molarity (M) or molality(m) to mathematically calculate and get a more accurate/more specific measurement of how much kool aid was combined with how much water. Molarity is a measure of how much solute is added to what volume of solvent.

Can you measure concentration with solids? ›

Solids concentration measurements are often used for interface detection in continuous processes where product-product and product-water interfaces occur during operation. A common industry where solids concentration measurements are used is the dairy industry as there are many such interfaces in a dairy/creamery.

How is solid concentration constant? ›

Since, both density and molar mass of a pure liquid or solid remains the same throughout the reaction at the same temperature and pressure, therefore, the molarity or concentration of pure solids and liquids remains constant throughout the reaction.

What is the concentration of a solid in solution? ›

When the solute in a solution is a solid, a convenient way to express the concentration is a mass percent (mass/mass), which is the grams of solute per 100g of solution.

What is the concentration of solids by volume? ›

What Does Solids By Volume Mean? Solids by volume refer to the percent ratio of the volume of dissolved solids (non-fluid particles) in a given mixture or solution relative to the overall three-dimensional linear space (i.e., total volume) that is occupied by said fluid mixture or solution.


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