Liquid Analyzers

What Is a Liquid Analyzer?

Liquid pH ORP analyzers and conductivity analysers are used for monitoring process chemistry including water quality, providing process optimization and control. Common measurements include pH, ORP, conductivity, resistivity, percent concentration, and dissolved oxygen.

What Are the Industrial Applications of Liquid Analyzers?

Industrial conductivity sensor
Chlor/Alkali Plant pH/ORP Measurements
Brine Manufacturing
Headbox pH Monitoring
Sugar Refinery pH Control
Dairy Waste Water Processing
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What Is Conductivity in Water Treatment?

In water treatment, water must pass a conductivity test to see if it passes an electrical current. Conductivity in water is related to inorganic solids, including ions carrying a negative charge (chloride, nitrate, sulfate, phosphate anions) and ions carrying a positive charge (sodium, magnesium, calcium, iron, aluminum cations). The conductivity level of water is also dependent on temperature.

What Are the Benefits of Liquid Analyzers?

Liquid analysis is essential for protecting critical and essential assets including boilers and cooling towers, by preventing corrosion, minimizing maintenance, and maximizing uptime.

Yokogawa is a recognized world leader for reliable liquid analytical equipment, providing accurate and repeatable solutions for maintaining and controlling even the most demanding process optimization and control applications with unparalleled ease of operation.

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Use our Liquid Analyzer Sensor Wiring Guide to easily find the correct wiring for your liquid analyzer sensor.

SENCOM™ SMART Digital Sensors

Reduce configuration time and simplify maintenance

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pH and ORP Analyzers

Optimize field maintenance, calibration, and system configuration

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pH and ORP Sensors

Ensure fluid process operations

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Conductivity Analyzers

Maintain and control even the most demanding process applications

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Conductivity Sensors

Measure aqueous solutions quickly and reliably

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Dissolved Oxygen Analyzers

Built to withstand the harshest applications

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Dissolved Oxygen Sensors

Perform liquid process measurement across multiple applications

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Turbidity Analyzers

Control and monitor water quality

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Chlorine Analyzers

Secure water quality with industry proven monitors

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Product Finder

This web tool makes it easier to find products according to the application, measurement conditions and required specifications.

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Reference

SCADA System Takes a New Municipal Water Treatment Plant in Bali to Higher Level of Operations

Application Note

pH/ORP Measurements for Chlor-Alkali Plants

Application Note

Brine Manufacturing

Application Note

Monitoring pH at the Headbox

Application Note

pH Control in Sugar Refineries

Application Note

Dairy Wastewater Processing

Application Note

pH in MICA - color pigment manufacturing

Featured eBook

Excellence in the Clean in Place (CIP) Process

Media Publication

Factors Affecting Reverse Osmosis Operation

(BN-P-20211012-01)

Edition 1 1

Tutorial

Back to Basics Webinar Series

Which Input Module do I order for my FLXA21/202 analyzer?

The input module you need depends on the Model Number of your FLXA Analyzer.

I have just purchased a pH or ORP Sensor from Yokogawa, what are the guidelines to follow in order to correctly install the sensor?

To prepare the sensor for installation follow the below steps: Carefully remove the watering cap. Rinse the sensor with water. Check the interior of the pH glass membrane for air bubbles. Allow any bubbles to rise to the top by shaking the sensor ge...

Are blank plugs supplied for the cable entry holes which will not be connected with conduit adapters?

Yes. It does not matter if an order for the conduit adapter (option) is entered or not, standard plastic cable glands and blank plugs are supplied by Yokogawa.

Why am I getting a temperature compensation 1 error on the analyzer?

(Thursday Tip 1)

Why am I getting a temperature compensation 1 error on the analyzer when I'm using either an inductive or contacting conductivity sensor? Common causes for temperature compensation errors.

Edition 1

Will the SA11 store alarms and fault information?

Yes, in the logbook of both the SSA and ID-chip inside sensor. Remark: when sensor is re-connected to SA11, the sensor logbook information will overwrite the logbook information inside the SA11.

How to enter temperature coefficient value in SSA?

1. Manually by using a HOST (FLXA402, Fieldmate) 2. By calibration of temp. coefficient Remark: it is a process calibration which is NOT sensor specific. This means it will not be stored in the sensor ID-chip.

Are there any apps available for the SSA like calibration, maintenance, setup, upload/download settings etc.?

No, FieldMate and FLXA402 are the only communication devices available to work with the SENCOM 4.0.

What area are classification ratings available on the SA11?

The area classification of the SA11 at the time of release is General Purposes with IP 67 rating for ingress protection. Once the FLXA 2-wire solution is upgraded to work with the SA11, all necessary certifications for Class I Div I and Class I Div I...

What does SA stand for?

SA stands for Sencom Adapter (Model SA11). This is one piece of a new product platform. The SENCOM 4.0 series has been released to replace the original SENCOM generation of products from Yokogawa. The new SENCOM 4.0 SA11 Smart Adapter uses ...

When will the EXA450G series be terminated?

The current termination of sales date for the EXA450G series is estimated to be around April of 2020. As the date gets closer announcements will be made. Following Yokogawa's normal practice, all spare parts will still be available for five ...

How can the BA11 active junction box be mounted?

The BA11 is delivered with a mounting bracket which can be attached to the back of a FLXA402 or FLXA202. It also can be used to mount the BA11 on a pipe or wall. ...

How can we mount the SA11 in the field?

In most cases the SA11 Smart Adapter is mounted directly on the sensor. If the temperature is high the temperature limits of the SA11 Smart Adapter (-30 up to +125°C (-22 up to +257°F)) may require that the adapter be remotely mounted. Optio...

What is the function of the switches on the back of the door of the FLXA402?

Slide switch #1 is to disable HART communications. Turn this switch OFF to ENABLE HART communications. Turn it ON to DISABLE HART communictions. Slide switch #2 is not for customer use. DO NOT TURN IT ON. Leave it in the OFF position. Th...

Can we use the same SA11 for different parameter measurements?

For example, initially, we used it for pH measurement, later we would like to use it with a conductivity sensor. No due to the variopin pin out allocation, there is a different SA11 Smart Adapter for each parameter. If the FLXA402 has a SENCOM...

What does the FLXA402 display look like when multiple sensors are connected?

If the FLXA402 has only one Analog Input Module the display will look like the Single Input above. If the FLXA402 has two Analog Input Modules the Display will look like the Dual Input above. You can select which input is active by clicking ...

Where can I find the Modbus registry mapping for the new SENCOM 4.0 products? Is it different from the “old” SENCOM?

The Modbus registers for the new Sencom 4.0 devices have changed, they are not the same is the older SENCOM devices. The SENCOM 4.0 Modbus Register information for the FLXA402 is available in TI12A01F01. You can download this document from...

Is there any option to restore factory set up in the SA11?

Yes. This setting only changes the SA11 setup parameters. It does not change the information stored in the ID-chip inside the sensor.

Can the SA11 + analog sensor be calibrated with the FLXA402 ?

Yes, that is possible. The calibration procedure is exactly the same as the standard analog sensors directly connected to the FLXA402.

What is the EMC rating for the SA11?

From the GS sheet you will find: EMC Regulatory Compliance: North America: EN 61326-1 (Class A, Table 2) EN 61326-2-3 Australia and New Zeeland: CISPR11 Korea: Electromagnetic ConformityStandard Class A Regulatory Compliance Mark Level...

What are pH Measurement and Calibration Best Practices?

(Thursday Tip 8)

Why is pH Calibration important? How to clean pH glass? Which pH buffers should I use? How fresh should pH buffer solution be? How long between calibrations?

Edition 1

Can the PH21 be used as an analog sensor?

Yes, it can be used as an analogue sensor connecting to the analog inputs of the pH transmitter. ...

Does the PH21 have a liquid Earth?

No, the PH21 does not have a Liquid Earth (LE) electrode. The LE is not needed in many of the applications we target for this sensor. When necessary a seperate Liquid Earth connection can be connected to the SA11 using the screw termin...

O-Rings for the PR20, PR4A, ISC40PR?

The PR20, PR4A, and ISC40PR were discontinued in April of 2010. The PR10 is the replacement for these products. It is larger than the PR20 so installation changes are necessary in most cases. The PR20 had a 1" NPT process connection, and th...

PH150 Forgot Password?

(KB-000-0209)

The PH150 allows the use of passwords to limit access to the Calibration functions and access to the Configuration functions. If these functions have been protected with a password and the password is not available there is a way to bypass the prote...

EXA450 Error 130, Error 131

(KB-000-0218)

Error 130 & 131 are display errors. The PH450 calibrates the display each time it powers up. Error 130 or 131 means this calibration failed. Cycle the power to the unit and allow it to calibrate the display again. If after 6 times the error is st...

I am seeing an Err-2 on my pH instrument. What does it mean?

(KB-000-0223)

An Error 2 means that the calculated asymmetry potential is outside the acceptable range. The Asymmetry Potential (AS), also referred to as the millivolt offset, is an indication of the condition of the reference electrode. Theoretically when the ele...

I am getting an Err-3 on my pH instrument. What does it mean?

(KB-000-0224)

The Error 3 is related to the slope value on a pH loop, indicating that the slope value is outside of the allowable range. The Slope (SL), also referred to as the efficiency of the electrode, is an indication of the condition of the pH electrode. The...

Is it possible to remove air bubbles from inside a pH probe?

(KB-000-0239)

Air bubbles are normal in pH sensors and in some reference sensors. They are necessary because the pH sensor is a sealed device with no vent. Without the air bubbles the expansion and contraction of the liquid with temperature changes could cause the...

Do the new Differential Cation sensors need to be recalibrated regularly?

(KB-000-0241)

Yes. The Cation Differential pH and ORP sensors have a glass electrode that needs a 2 point calibration performed regularly. Because of the Cation Reverence electrode you must use special buffers with a constant sodium ion concent...

Errors resulting from cracked glass electrodes.

(KB-000-0244)

A tiny crack in the membrane of a glass electrode is not always visible to the naked eye. Frequent shocks may create cracks in the glass that cause measurment errors. These cracks will cause the analyzer to read 0 mV and the ...

Errors caused by wet cables or bad connections.

(KB-000-0245)

It is very important that the cables maintain a very high impedance. If any moisture penetrates the cable the impedance will drop and the cable will short out the voltage generated by the pH sensors. This will cause errors or a total loss of mea...

Errors caused by shorting the electrode cables

(KB-000-0246)

Often, Instrumentation technicians like to shorten cables to match the installation. This is strongly discouraged with Analytical Sensors. Yokogawa has designed cables with a special layer of conductive plastic to ensure maximum noise ...

What happens if we combine a measuring electrode with 3.3 mol KCl electrolyte with a reference electrode with 1 mol KCl in a pH sensor or vice versa?

(KB-000-0262)

The reference potential difference between 1 molar and 3.3 molar is approximately 30 mV. The sensitivity of a pH sensor at reference temperature is 59mV/pH. So if you combine a measuring cell filled with 3.3mol KCl with a reference cell with 1mol KCl...

What is the shelf life of a buffer solution? How long does it last after the bottle is opened?

(KB-000-0278)

Yokogawa's buffer solutions have a guaranteed shelf life of 12 months from the date of shipment. The exception to this is the sodium buffer solutions used to calibrate the differential pH sensors (part numbers K1520BF, K1520BG, K1520BH, K152...

How many pH analyzers can I calibrate with the same buffer solution?

(KB-000-0280)

We recommend using pH buffers only once. If you want to use the same buffers for more analyzers, then you must avoid contamination of the buffers by the sensors. The sensor must be cleaned and washed carefully before inserted into the buffer. A senso...

Is it possible to connect competitor's sensors with Yokogawa analyzers? If yes, what are the conditions?

(KB-000-0287)

All Yokogawa analyzers use an open architecture with adjustable temperature compensation, adjustable isopotential point, and adjustable slope. They are compatible with all direct pH, ORP, and conductivity sensors. There are two exceptions to th...

Can I improve the life of pH sensor when I choose 225 mm electrode in place of 120 mm electrode?

(KB-000-0311)

That is possible but not guaranteed. The 225 mm sensor body is longer, so it has more electrolyte. Often the reference electrode fails because the electrolyte is depleted as it diffuses through the reference junction into the process. With ...

Can we mount pH sensors upside down?

(KB-000-0312)

Most pH sensors with a glass membrane cannot be mounted upside down. To absorb the thermal expansion of the internal buffer solution there is always a sizeable air bubble inside the sensor. When the sensor is mounted upside down the reference element...

Does Yokogawa offer a nonglass pH electrode?

(KB-000-0313)

Yokogawa offers the PH18 sensor. This sensor is nonglass and suitable for regular CIP and SIP cycles. ...

In a dual input FLXA202 or FLXA21 analyzer, how can I see the values from the second input module?

(KB-000-0316)

In a dual input FLXA202 or FLXA21 analyzer you can use a HART Splitter to convert the HART® dynamic variables into current outputs or contact outputs. The model number is "1W-KFD2-HLC-EX1.D" and the description is "P+F HART Splitte...

Can we use a pH analyzer as a temperature analyzer? If so, how?

(KB-000-0317)

Yokogawa's pH and conductivity sensors include a temperature sensor to allow for temperature compensation. The pH and conductivity sensors have a relatively large temperature mass and respond slowly to the changes in the process temperature. This...

How accurate is your pH analyzer?

(KB-000-0319)

Generally we state that the pH analyzer is as accurate as the care that is given to the device allows. With lots of care you can achieve 0.05 pH accuracy. With normal care you achieve 0.1 pH Without care the measuring error can be pH 0.5 or more...

Where do I find documentation for the PH150?

(KB-000-0366)

The PH150 and SC150 were discontinued in 2004. The Manual and General Specification sheet are no longer available on Yokogawa's website. Use this link to download a zip file containing both documents.

Where do I find documentation for the TM20?

(KB-000-0370)

The TM20 pH meter was discontinued over 20 years ago, but the manual is still available. If you have trouble downloading it, send us an email at yca-support@yokogawa.com or call 800-524-7378.

FLXA21 or FLXA202 Check Sum Error

(KB-000-0372)

First, check the grounding. A bad ground can cause this failure. Next: cycle the power to the unit. Shut the power off for 30 seconds then restart. If that doesn’t clear the error reset the analyzer to factory defaults. Be ...

Which is more accurate when performing an ORP calibration: one point or two point?

(KB-000-0376)

Performing a two point calibration for an ORP sensor may make a user more confident in the measurement because it ties the measurement to two known millivolt values, offsets and slope values. When performing a pH calibration, the 2nd point&...

SC150 - Lost or Forgot the Password

(KB-000-0385)

If you have lost the password for your SC150 you can use password #PW123# to get into the menu. The next thing you should do is to reset the password.

PH200, SC200, IC200, PH202, SC202, IC202, ISC202, PH402, SC402, DC402, IC402, ISC402, DO402, GD402 - forgot password

(KB-000-0389)

If you forget the password you have set in one of these transmitters there are only 9 passwords that can be set. The password setting on the unit is a little difficult to understand. When you put a 3 digit code in service code 52 you are setti...

Conductivity Sensor Cleaning

(KB-000-0391)

Soak the sensor in 5 - 10% Hydrochloric acid (HCl) in water solution. for 5 - 10 minutes, then rinse. If you have trouble finding 5 - 10% HCL you can buy muriatic acid at a building supply house and it is usually 20 - 30% HCL. Check the label. Dilute...

FLXA21 or FLXA202 - PH, Conductivity, ISC, or DO Transmitters - Forgot Password

(KB-000-0393)

If you forgot the password to your FLXA Transmitter you can use the password #PW123# - this will allow you go into the menus. Remember to change or remove the password.

SC200/202/400/402/450/FLXA21/FLXA202/DC400/DC402 Testing or simulating a contacting conductivity input

(KB-000-0394)

To test the conductivity input do the following: Write down the cell constant and change it to 1.00 (this is not mandatory, it makes the math easier) Place a jumper wire between 13 to 14 and another one on 15 to 16 (not necessary on t...

DC402 Turning off alarms on unused second input

(KB-000-0395)

There is no way to "turn off" an unused input on a DC402. If you leave the terminals open you will get error messages. Connect a simulated sensor to the unused input to clear the errors. Use a resistor on 11-12 to simulate the t...

What is the difference between a SC41 and a SC42 sensor?

(KB-000-0397)

The difference is the temperature sensor. The SC41 has a Ni100 temperature element and the SC42 has a PT1000 temperature element. PT1000 is a better temperature element, but some old electronics will not accept a PT1000 temperature element, so the SC...

Where do I find documentation for the SC150?

(KB-000-0402)

Use the link at the top of the page to download a compressed (ZIP) file containing the GS Sheet and Manual for the SC150.

How to test a ISC40G sensor

(KB-000-0404)

With an Ohm meter check the following wires on the ISC40G sensor cable: 11 to 12 (Pt1000 or Thermistor) 13 to 17 – Sensor coil – expect low resistance. If unstable or above 100Ω it is bad. 15 to 16 - Sensor coil – ex...

How can I test an ISC Converter?

(KB-000-0405)

You can test the ISC converter by simulating a conductivity reading using an ISC40 sensor. You will need: A known working ISC40 sensor. A piece of wire One or two decade box/resistance sources. Connect sensor wires 13-17 to analyzer. ...

Where do I find documentation for the DO400?

(KB-000-0406)

Click the link at the top of the page to download the DO400 Manual.

Oxygold G DO sensor Maintenance

(KB-000-0407)

How to startup a new sensor, or how to replace the Membrane Cap and Electrolyte. Startup of a new Oxygold G sensor: The Oxygold G sensor is shipped dry with a protective cap over the end of the Membrane Cartridge. CAUTION: The electrolyte ...

Can pH and ORP be measured simultaneously?

(KB-000-0321)

Most of our pH sensors have a noble metal solution ground and our transmitters measures two values: 1. the voltage between this solution ground, or liquid earth sensor and the pH sensor, and 2. the voltage between this solut...

How can be the process reading be wrong when it is correct in the pH buffers?

(KB-000-0324)

This is a well-known pH problem that we call Diffusion Potential. If the sensor junction is partially plugged the electrical contact between electrolyte and process is not good. This results in a high diffusion potential and an error i...

Can a reference electrode be stored in demineralized, deionized, or distilled water?

(KB-000-0325)

NO! Sensors that are not used need to be stored in a solution that guarantees that the sensor is ready for use. When the sensor is stored in pure water the salt will be washed out of the junction of the reference cell. This causes the sensor t...

Do I need to re-calibrate after cleaning my pH-electrode?

(KB-000-0328)

Yes and No. Yes - after cleaning you need to verify that the analyzer is reading correctly. The easiest way is to see how it reads when placed in 2 pH buffer soltuions. This is what you do when calibrating. No - If the readings are with...

How to refill a SR20-AC32 Bellomatic sensor? How to remove the electrode from the top of a Bellowmatic sensor if it is stuck?

(KB-000-0331)

First - when you receive a new Bellomatic sensor it is shipped with a rubber stopper inserted into the pressure port on the bottom of the sensor. You must remove this stopper before putting the sensor in service. DO NOT DISCARD THIS STOPPER! Put it i...

Can the FU20F or FU24F SENCOM sensors be used to measure pH and ORP at the same time?

(KB-000-0345)

Yes, the SENCOM Module in these sensors allows a Modbus Master to connect using Modbus RTU protocol and access the following data: pH Temperature compensated pH ORP pH compensated ORP rH Temperature Junction resistance value Sensor details ...

FU20, FU24 or PH20 looks like it leaked in the box

(KB-000-0364)

Can I use my FU20 or FU24 pH sensor in a Tank by just dropping it in the tank?

(KB-000-0365)

The short answer to this question is NO. But, there is a long answer that will give you another option. Yokogawa has created a Submersible Sensor Kit (part number M1289XT) for the FU20 pH sensors - M1289XU for the FU24 sensor). It is also known as ...

PH Sensor Cleaning

(KB-000-0380)

Cleaning pH Sensors Basic Steps Rinse electrode in clean water Clean by immersing the electrodes in a cleaning solution (see below). Rinse Again Check with buffers Cleaning Solutions: If you know a specific way to clean the sens...

What is the expected lifetime of a pH sensor?

(KB-000-0382)

Sensor lifetime is difficult to predict as it is dependent on a number of different factors such as pH value, temperature, pressure, the composition of the process liquid, maintenance activity is taken, storage conditions, and sensor handling. ...

I have a pH sensor that does not have a solution ground. Can I use it with a Yokogawa Transmitter?

(KB-000-0384)

Yes you can, but we do not recommend this method. A pH sensor has a reference electrode that has a low impedance to the process. If the process suffers from common mode voltages or ground loops it will be difficult to measure the ...

How to order a FF20 with a FU20 pH Sensor.

(KB-000-0408)

The FF20 flow through holder for PH can be ordered using the "pH Selection Guide Matrix" so that an entire system can be ordered with one line item. This does not work if you want a FF20 with an FU20 sensor. The Matrix does not contain the ...

ZA8C I forgot the password to get into Maintenance mode

(KB-000-0435)

The password to get in all the maintenance and commissioning menus is 16

ZR22S: Option "B" Adder

(KB-000-0438)

This is the Japanese GS sheet, containing a number of options we rarely sell here in the US. Contact Support at 800-524-7378 or support@us.yokogawa.com for price and delivery information. ...