Thermo Orion Process Products are largely under the Chemical Analysis Instruments HS category.
- As of March 4th, 2025 there are no tariffs on this category of HS code.
- Products are made worldwide so tariffs would only apply if made in the USA. Some Thermo brand products are made right here in Canada!
Example: 211190/91 DIPA for the Model 2111XP/LL Sodium Analyzers – NOT made in the USA. We do anticipate any tariff on this popular item.
Questions about your specific product, email sales@iccontrols.com
There are two ways to measure TDS – Total Dissolved Solids:
1. The gravimetric method is considered the most accurate and involves evaporating the sample to dryness at 103 °C, then to 180 °C to remove any occluded water, then weighing it with a precision balance capable of 0.0001 gram. Gravimetric analysis is best, although slow, and has inaccuracies from evaporation of low
boiling point chemicals. Use the result to adjust the TDS analyzer‘s solids content factor to achieve the reading.
2. By use of known TDS standards. IC Controls offers TDS standards as sodium chloride ppm or mg/L, made with NIST SRM traceable materials. Calibration
becomes simply a mater of dipping the TDS sensor into the selected standard and calibrating.
Learn more:
- Blog – Meeting Environmental Standards for TDS in Wastewater Treatment
- Technical Article – Total Dissolved Solids Measurement
Parts per million TDS or ppm (abbreviated) is an expression of quantity, mg/L (milligrams per liter) is an expression of weight. Both are used as scales
for TDS, but ppm is more popular. There is no conversion factor since 1 ppm = 1 mg/L.
Learn more:
- Blog – Meeting Environmental Standards for TDS in Wastewater Treatment
- Technical Article – Total Dissolved Solids Measurement
TDS ions from dissolved solids create the ability for water to conduct an electrical current, which is measured by the IC Controls 210-C(TDS) analyzer and immediately displayed as sodium chloride ppm or mg/L, or as a conductivity analyzer displayed as µS/cm. When directly measured in process the conductivity detected is not neutralized. IC Controls 210-C(TDS) analyzer has an adjustable SCF solids content factor to match your application.
Typical non neutralized TDS solids content factors:
TDS as NaCl: 0.47 to 0.50
TDS as 442®: 0.65 to 0.85
TDS as KCl: 0.50 to 0.57
Learn more:
- Blog – Meeting Environmental Standards for TDS in Wastewater Treatment
- Technical Article – Total Dissolved Solids Measurement
There are two principal methods of measuring total dissolved solids: gravimetic and conductivity. The standard method is gravimetric, which is considered the most accurate and involves evaporating the sample to dryness at 103 °C, then to 180 °C to remove any occluded water, (water molecules trapped in mineral matrix), then weighing it with a precision analytical balance (normally capable of 0.0001 gram accuracy). This method is generally considered best, although it is
slow and has inaccuracies from low-boiling-point chemicals which evaporate with the water.
TDS of water is directly related to the conductivity of dissolved ionized solids in the water. Ions from the dissolved solids create the ability for water to conduct an electrical current, which is measured by the IC Controls 210-C(TDS) analyzer, and immediately displayed as sodium chloride ppm or mg/L or µS/cm conductivity. When periodically standardized with IC Controls TDS standards or by laboratory gravimetric TDS measurement, TDS analyzers based on conductivity provide a quick accurate value of the TDS.
Learn more:
- Blog – Meeting Environmental Standards for TDS in Wastewater Treatment
- Technical Article – Total Dissolved Solids Measurement
Total Dissolved Solids (TDS) is a measure of the sum of all inorganic and organic substances in a liquid in molecular, ionized or micro-granular colloidal suspended form. The solids must be small enough to survive filtration through a sieve the size of two micrometer. TDS solids are normally found in all freshwater systems. Major applications of TDS are: at low levels the study of water quality for streams, rivers, lakes, potable water taste, and at high levels the control of scale in recirculating water systems. It is a quality indicator for drinking water and is a general measure of the presence of chemicals. In seawater RO desalination, TDS provides a way of comparing the feed with the permeate quality that is relevant to drinking water taste standards.
Total Suspended Solids (TSS), are different from TDS as they cannot pass through a sieve of two micrometers and are suspended in solution. Flocculation and sand filtration can remove settleable solids and suspended solids from the water but dissolved TDS solids are not removed.
Learn more:
- Blog – Meeting Environmental Standards for TDS in Wastewater Treatment
- Technical Article – Total Dissolved Solids Measurement
- View – TDS Analyzer, TDS Sensors, TDS Standards
Drinking Water and Well Water applications where the user needs to control the chlorination due to active disinfecting, measure Free Available Chlorine and Total Free Chlorine.
- Free Available Chlorine measurement – is used when you have steady, predictable pH.
- Total Free Chlorine measurement – is used when you have variable/ unpredictable pH and/ or where improved accuracy is necessary.
- Read Technical Article – Chlorine Theory and Measurement. Learn
Effluent Water applications where the user needs to control/monitor/quench the dechlorination, measure Total Residual Chlorine (TRO).
- Read blog – Measure TRO for regulatory compliance. Learn how to verify the absence of chlorine and how to safely discharge effluent back into natural bodies of water.
- Total Residual Chlorine (TRO) analyzer
There is a big difference in the chlorination levels being measured between Free Available Chlorine / Total Free Chlorine and Total Residual Chlorine.
Free Available Chlorine refers to the hypochlorous acid (HOCl) form of chlorine only. It is the free, uncombined form of chlorine that is effective for disinfection. View Free Available Chlorine Analyzer – Model 875-25
Total Free Chlorine refers to the sum of hypochlorous acid (HOCl) and hypochlorite ion OCl-). The hypochlorite ion is not effective for disinfection, but it is in a free form. All of the total free chlorine would be in the form of hypochlorous acid if the pH was low enough. View Total Free Chlorine Analyzer – Model 876-25
Combined Chlorine refers to chlorine which is not readily available. For example, chlorine combined as chloramines or organic nitrogen is not an effective disinfectant and will not readily convert to hypochlorous acid or hypochlorite ion.
Total Residual Chlorine refers to the sum of total free chlorine and combined chlorine. Low total residual chlorine is of particular interest to ensure there are no downstream consequences for aquatic life. View Total Residual Oxidant Analyzer – Model 7070iX
The primary ongoing maintenance item in the ppb Dissolved Oxygen measurement system is the membrane module on the sensor. It may need to be replaced once or twice a year depending on the application and installation. Portable ppb Dissolved Oxygen systems such as the Model 869 needs may need more maintenance than the Model 865-25 panel mount system because the portable system is moved around and sees different sample conditions.
Tips to prolong the life of your dissolved oxygen sensor.
- When removing the sensor, open the drain to atmospheric pressure.
- When storing the sensor, keep it in a sealed flowcell with zero DO solution or a low ppb sample. Keep the analyzer powered.
- Minimize exposure to ppm level concentrations. ie: 1 hour.
- Sample: 5 to 60C, <60 psi (note: 869-22 has no regulator), flowrate 50 to 200 mL/minute.
- Particulate filtration or grit bypass (note: 865-25-80 has a grit bypass)
Galvanic Dissolved Oxygen measurement is better than Optical Dissolved Oxygen when users needs resolution below 10 ppb. This typically means industrial plants using high pressure steam generation (approximately 600 psi or greater), semiconductor fabrication plants and other ultra pure water applications. Galvanic offers better accuracy and read to much lower levels – IC Controls galvanic products reads down accurately to tenths of a ppb – see link. It is known that electrochemical sensors such as galvanic sensor offer superior resolution in this range over optical sensors. See Suez (formerly GE Water) guidelines for boiler support low DO levels.
Galvanic Dissolved Oxygen analyzer systems:
- 1816DO Thermo Orion – online ppb Dissolved Oxygen System – specifications
- 865-25 IC Controls – ppb Dissolved Oxygen Panel – specifications (For sale by IC Controls worldwide)
- 869 IC Controls – portable ppb Dissolved Oxygen System – specifications (For sale by IC Controls worldwide)
Optical Dissolved Oxygen measurement system:
- RDO – Thermo Orion (For sale by IC Controls in Canada only)
Learn more about ppb Dissolved Oxygen
The shelf life of a ppb Dissolved Oxygen probe or Dissolved Oxygen Sensor is 5 years when stored in it’s original packaging. Once you add humidity and temperature, consult the specifications.
- 1816DO Thermo Orion – online ppb Dissolved Oxygen System – specifications
- 865-25 IC Controls – ppb Dissolved Oxygen Panel – specifications
- 869 IC Controls – portable ppb Dissolved Oxygen System – specifications
Learn more about ppb Dissolved Oxygen
IC Controls has specially trained technicians to service and repair your Thermo Orion Process equipment. We are the only authorized provider of service and training on Thermo Orion products in Canada.
- Learn more – Field Service Start Ups
- Learn more – Shop Service & Repairs
- Learn more – Rental Equipment while your equipment is being serviced.
IC Controls supplies Thermo Scientific Orion Products View – list of SKUs.
- Learn more – Process Monitors
- Learn more – AquaSensors products
- Learn more – Laboratory products
IC Controls provides warranty replacements and repairs for the country of Canada.
Yes! IC Controls stocks and ships from our factory in Canada.
IC Controls is the master distributor for Thermo Scientific Orion Process products for the country of Canada since 1979.
“It has been a pleasure working with you over the past several years, and I truly wish you all the best. I believe IC Controls sets the gold standard for Thermo Fisher process distributors, and I’ve been consistently impressed with the professionalism and overall pleasantness of everyone I’ve worked with there.” December 2025 Thermo Fisher Scientific, Greg Puetz
Pulp fibers get caught in the area around the glass, clogging the electrode. Once clogged with pulp fibers the reference and glass to no longer have contact with the process, so pH measurements wander. There are two different electrode modifications to help alleviate the clogging problem. One is a flat pH glass tip (IC Controls sensor option – 6). Benefits of Flat Glass: – reduces crevices to clog, – minimizes direct impact on glass. Disadvantages of Flat Glass; surface is parallel to flow so does not contact liquid sample as well, – glass has 90º angle which can break do to thermal stress. Another proven pH sensor design incorporates a domed pH glass in a pulp modified tip (IC Controls sensor option – 73), to ensure better contact with the solution while protecting the tip from the shearing action of the stock and clogging. Benefits of Pulp Modified: – Domed pH Glass stronger in thermal stress applications, – Tip Protected from shearing of dense stock, – De watering on the electrode edge for better pH response, – Flow over surface on domed glass provides more accurate pH results.
To combat reference contamination, double junction and/or plasticized references are used to slow down the migration of the sulfide or cyanide to the reference wire. The second junction (IC Controls sensor option – 7) will to increase the path length of the contaminants to the reference wire. The longer the migration path, the longer it will take to reach the reference wire, extending the life of the reference. The second junction also forms a chamber which will slow the migration ions, again extending reference life. A second contamination deterrent is a plasticized reference solution (IC Controls sensor option – 8). The plasticized reference impedes ion migrates as a solid as opposed to a liquid. The more solid the reference solution, the longer contaminant migration will take thus protecting the silver/silver chloride wire.
pH sensors with porous reference junctions allow KCl to migrate through the junction into the process to complete the electrochemical connection. Since the junction is porous, some aggressive processes can also migrate ions into the reference, causing contamination and premature failure. As the process migrates into the reference it may attack the silver/silver chloride wire, changing its chemistry which results in the electrode drifting. This is seen as an offset away from zero mV during calibration. There are a number of different constituents that can contaminate the reference electrode. Two major contaminates in the industrial market are sulfide (S2-) and cyanide (CN-). Sulfide is commonly found in kraft pulp and paper mills, mines and oil refineries. All of the different liquors in the kraft process have a high sulfide content and therefore, the pulp stock will have a significant amount of sulfide as well. Cyanide, is typically found in mines, metal refineries, and electroplating. The cyanide is for metal separation in flotation cells. Thus, contamination of the reference is an issue for both pH and ORP sensors which are used in these processes.
If the pH response becomes sluggish and the slope of the probe starts to get too low, IC Controls Electrode Renew Solution can be used (P/N A1100092). The electrode renew solution will skim off a micro-layer of the coated glass, thereby exposing a new glass surface which will exhibit better pH response.
In the past, a hydrochloric acid (HCl) solution was used to remove scale form the tip of the electrode. Although this has been somewhat effective, IC Controls’ gentle scale remover, P/N A1100094, will better clean the electrode. You can also try using liquid detergent to remove minor coatings.
Electrode storage solution is best (IC Controls P/N A1100090). Your next best option is 7 pH buffer (IC Controls P/N A1100018). You can use tap water but the pH glass and pH reference will continue to age as if in the process.
You can soak it overnight in water with a pH of 2. Or you can use electrode renew solution (IC Controls P/N A1100092). You may also refer to our maintenance tips presentation, listed on our website under service/support, maintenance tips #5: Extending the life of old sensors
– In applications normally above pH 10, use High pH glass (IC Controls sensor option -3)
– Wash the sensor in acid to refresh it (IC Controls P/N A1100091)
– If sensor becomes very sluggish, use pH sensor renew solution (IC Controls P/N A1100092) to replenish pH glass surface
A caustic (sodium) ion error occurs when the concentration of hydrogen ions is low (when pH is high). As the pH goes up, the concentration of hydrogen ion goes down, at the same time the concentration of sodium ion will increase. Sodium is very close to hydrogen in its chemical structure. As the concentration of hydrogen ions decrease, the glass will start to recognize sodium as hydrogen, giving a false and therefor lower pH reading.
To revive or speed up the pH Sensor immerse it in a beaker of 4 pH buffer (lots of hydrogen ions) until the reading gets relatively close to pH 4. Rinse off the electrode and place it in pH 7 buffer until the reading gets relatively close to to pH 7. Keep alternating between 4 and 7 buffer until the response time is normal.
Sluggish response is likely to occur when an electrode is taken out of long storage due to hydrolysis of the pH electrode glass membrane. The electrode is stored in salt water which is best for the reference, but is not hydrogen ion rich, as is best suited for the pH glass.
Do a speed of response test. If it takes over 3 minutes to receive accurate readings when going from 7 pH to 4 pH, then it is time to either clean or replace your sensor.
First inspect the sensor to make sure there is no damage. Then hold the sensor vertically and carefully remove the protective cap (typically black or red) from the sensor tip. Calibrate the sensor and place it in service. IC Controls pH sensors are shipped with a protective cap containing pH electrode storage solution. The storage solution extends the life of the pH reference electrode during storage. If the sensor needs to be returned to stock, carefully replace the protective cap including the storage solution. Check out our YouTube video.
Method 1: Mechanical cleaning
On sludge, slime, or other soft deposits, mechanical cleaning can be used. Clean with a soft brush and a beaker or bucket of water. General debris and non-tenacious deposits can be removed in this way. On hard scale, a standard flat screwdriver blade can be used to carefully scrape hard scale and other tenacious deposits off the reference junction. The IC Controls 642 open tip design also allows a screwdriver to carefully score and crack hard scale against the glass shaft, then carefully slide it up and off the pH glass tip without touching the pH glass. After mechanical cleaning, again check the sensor against a pH buffer. If the sensor is still not developing the proper pH reading in the buffer you can proceed to a second cleaning method.
Method 2: Chemical cleaning
Chemical cleaning is a bit more involved, so IC Controls has made available a Chemical Cleaning Kit (IC Controls P/N A1600054). This kit contains all required supplies along with a complete instruction sheet to enable you to complete a chemical cleaning on your sensors.
Yes, many of our MSDS sheets are available for download in French. Go to our website as above and select the link with the description “French”. Please contact IC Controls if the MSDS you require is not on the website.
IC Controls recommends PT1000 (option -34) as it offers approximately 10 times better accuracy in most situations compared to PT100 (option -32).
pH or other liquid analysis sensors are often installed in humid environments with long signal lines, signal lead connections, and temperature fluctuations. PT100 changes 0.385 ohms per degree C; good clean signal lead connections often exhibit 0.2 ohms resistance to which 4 or 5 ohms resistance can be added from humidity resulting in about a 13 degree C temperature error. This is even before considering the copper lead resistance change effect on temperature compensation accuracy. In contrast, the PT1000 changes at 3.85 ohms per degree C translating into a clean connection error of about 0.05% and reducing humidity/corrosion induced temperature error to about 1.3 degrees C.
When IC Controls sensors are connected to a non-IC Controls analyzer, we strongly recommend verifying whether the analyzer can be used with PT1000 temperature compensation in order to achieve the better TC accuracy. If PT1000 is possible, option -34 should be specified in the IC Controls sensor. Only in the event that PT1000 cannot be used should option -32 be specified recognizing that temperature compensation and measurement will be less accurate.
Conductivity is measured by determining the amount of current that can be carried between two electrodes by a known amount of liquid. To determine the amount of current that will flow through a “known amount of liquid”, the volume between the two electrodes must be exact. This precise volume is known as the Cell Constant. The cell constant is a multiplier constant specific to a conductivity sensor. The measured current is multiplied by the cell constant to determine the electrical conductivity of the solution. The cell constant, known as K, refers to a theoretical electrode consisting of two 1 cm square plates 1 cm apart. A cell constant has units of 1/cm (per centimeter), where the number refers to the ratio of the distance between the electrode plates to the surface area of the plate.
How can we prevent coating of the pH Glass?
Coating of the glass causes poor contact between the glass itself and the process. Good contact by the electrode is essential for quick, accurate response in the process. Thus, to help keep the glass clean and responsive, there are a couple of techniques that can be used. IC Controls sensors are designed with two flutes to allow self cleaning. By turning the flutes to 75°, the process does not directly hit the glass which will slow down the coating action. Therefore, there is no mechanical cleaning which increases reliability and reduces maintenance. Insert the electrode with the flutes at 75° to flow. By inserting the probe at this angle a vortex will be created around the glass. The vortex will increase the velocity of the process around the glass and reference which will, in return, hasten electrode response time and keep the reference and glass cleaner. This approach is particularly beneficial where sharp, fines material can wear away any lime buildup.
Advantages:
– No Mechanical Parts to Fail
– Longer Sensor Life
– Less Maintenance
– Better pH Response
In application where the flow is stagnant, or not linear, or the coating is soft, a chemical spray cleaner can be attached to the tip of the pH sensor. Mounting the spray cleaner on the tip allows timed intervals of automatic cleaning without operator handling or maintenance. Spray cleaning also allows choice of the best chemical for cleaning the pH sensor and improving response.
Advantages:
– Reduced Operator Handling
– Longer Sensor Life
– Less Maintenance
– Better pH Response
How can you clear a scale coated pH Sensor?
In the past, a hydrochloric acid (HCl) solution was used to remove scale form the tip of the electrode. Although this has been somewhat effective, IC Controls’ gentle scale remover, P/N A1100094, will better clean the electrode. You can also try using liquid detergent to remove minor coatings.
Why does IC Controls use Silver/Silver Chloride pH Reference Electrodes?
The silver/silver chloride (or Ag/AgCl) reference has advantages for use in the industrial pH market. First, the temperature stability is good in applications ranging up to 105ºC (220ºF). Plus, with stabilizers added, accurate pH measurements can be taken to temperatures in excess of 125ºC (260ºF). The silver/silver chloride reference has become an IC Controls standard.
Why not use Calomel vs. Silver/Silver Chloride Reference?
Like the glass electrode there are also different types of reference electrodes that can be utilized in any given pH measurement. The two common references are the calomel electrode and the silver/silver chloride reference. The Calomel electrode is not used in industrial applications because the electrode breaks down when the temperature exceeds 80ºC or 175ºF. It is also part mercury, which is a health hazard.
How Do Glass pH Electrodes Work?
The glass electrode basically consists of four major components, a glass membrane, an internal buffer solution, a reference wire and the glass stem. The pH glass electrode works with two reference electrodes, a reference inside the glass and a reference that is in contact with the solution outside of the glass. pH measures the milli-volt difference in the pH electrode system. A leached layer forms on both sides of the pH glass membrane. The difference in potential between the inner and outer layers is called the phase boundary potential and is the potential milli-volt difference that is the pH signal. For best results, a symmetrical liquid cell is set up on both sides of the glass membrane. To set up the symmetrical cell, the internal fill solution in the glass and the reference fill solution are similar in their makeup. The symmetry is important so that the temperature curves for the two solutions are close, thereby canceling each others temperature effect.
How Do pH Reference Electrodes Work?
Reference electrodes work like a battery with the chemical components producing a predictable millivoltage, that is also in electrical contact with the solution being measured. The reference is a constant millivoltage thus, giving the glass a reference point to distinguish changes in Hydrogen ion concentration seen as a potential across the leached layers.
Learn more about pH sensors:
- Blog – Importance of Accurate pH Monitoring and Control
- Blog – pH Sensor Life in Harsh Applications
- Technical Articles – pH Sensor in Metallurgical Applications
- Technical Articles – How Electrode Design Correlates with Optimum Performance in pH Measurement
- Technical Articles – High Purity pH Measurement
- Technical Articles – The Right pH Electrode for Steam Cycle Monitoring and Control
- Technical Articles – Reliable pH Measurement in Oily Applications
- Technical Articles – Modern Sustainable Cyanide Destruction
View pH sensor mounting options – Insertion, Submersion or Ball-valve retractable
- Cleaning pH Sensors, part 1 Tip
- Cleaning pH Sensors, part 2 Tip
- Preventative Measures Tip
- The Effects of Scale Tip
- Extending the life of old sensors Tip
- Like new reading from old pH sensors
Typically they should be replaced every 3 years. To be sure you have the most updated version, go to our website and check the date on the MSDS sheet under “preparation”. If there is a newer date, then replace your current version.
Yes, Thermo Orion 2100XP series monitors are CSA and CE Certified.
Dissolved Oxygen (D.O.) is the amount of oxygen gas dissolved in a given quantity of solvent, usually water, at a given temperature and atmospheric pressure. It is usually expressed as a concentration in parts per million (ppm) or mg/L. For trace level of dissolved oxygen, parts per billion or µg/L is the unit typically used. D.O. The concentration can also be expressed as percent saturation, where saturation is the maximum amount of oxygen that can theoretically be dissolved in water at a given pressure and temperature.
Electrical conductivity is a measure of the ability of a solution to carry a current. It is defined as the reciprocal or resistance, in ohms, of a 1 cm cube of liquid at a specified temperature which is expressed as siemens/cm. Current flow in liquids must be carried by ions. Ions are formed when a solid such as salt is dissolved in a liquid. For example, sodium chloride separates to form Na+ and Cl- ions. All ions present in the solutions contribute to the current that can flow through the sensor and therefore, contribute to the conductivity measurement. Electrical conductivity therefore is a measure of the concentration of ionizable solutes present in the sample.
Chlorine (symbol Cl) is a chemical element which can be found in the earth and the oceans. It is a greenish yellow gas at room temperature, and it is 2.5 times heavier than air. It turns to a liquid state at -34ºC (-29ºF), and it becomes a yellowish crystalline solid at -103ºC (-153ºF). Chlorine is highly chemically active and, as such, is typically found in nature bonded to other elements like sodium, potassium and magnesium.
What is pH? The everyday answer:
pH is a short form for the power (p) of Hydrogen (H), which is a way of expressing the measurement of the hydrogen ion concentration. The pH scale is the way to express how acidic or basic a solution is. The pH scale is 0-14, where a pH of 0 to 6 (or 6.9) is a acidic, 7 (or +/- 0.9 around 7) is neutral, and a pH above 8 (or 7.1) to 14 is basic or alkali. Because ions come in massive numbers the measurements are made using logarithms, so pH 7 is neutral, pH 6 has 10 times more Hydrogen (H), pH 5 has 100 times more Hydrogen (H) than 7, . . . until pH 0 has 10,000,000 times more Hydrogen (H) than 7.
What is pH? The Chemists expanded answer:
A pH sensor will measure the activity of the hydrogen ion. Since the activity of the hydrogen ion is nearly identical to the concentration of the hydrogen ion, the practical definition is p[H] = -log[H+]. The concentration of hydrogen ion typically lies between 10E-14 and 10E0 mol/L. It is therefore convenient to express hydrogen ion concentration using the pH scale where p becomes an operator which says: “take the base 10 logarithm and multiply by -1.”
