Process Analyzers

Improving the operation, reliability, and credibility of online process analyzers

Process analyzers are on-line tools for industrial process analytics, used to determine the chemical composition or physical properties of substances involved in industrial processes. They enable process optimization, asset protection, and compliance with environmental regulations.

With one of the most comprehensive families of sensors and on-line analyzers for pH, conductivity, dissolved oxygen, combustion oxygen, humidity, liquid and gas density and process gas chromatography, Yokogawa is recognized as a world leader in the field of analytical equipment. Accurate, repeatable measurement is the key to obtaining optimal results in your process, and Yokogawa's diagnostic-based analytical instrumentation offers the flexibility to meet a range of individual requirements. Whether for liquid or gas applications, our analyzers can resolve even the most demanding situations. Yokogawa's leadership in process analytics helps to protect the environment by reducing energy consumption and CO₂ emissions.

Gas Analyzers

Real-time gas analysis enhances efficiency, safety, throughput, product quality, and ensures environmental compliance.

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Liquid Analyzers

Liquid analyzers are used for monitoring process chemistry including water quality, providing process optimization and control.

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Process Analyzer Systems Integration

Analytical solutions for gas and liquid measurements to support product refinement, process efficiency, and safety.

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Analytical Services

Our analytical services include installation and construction, startup and commissioning, and training services.

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eBook

Boiler Optimization Toolkit

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Improving Analytics to Meet Process Industry Demands

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Refinery of the Future

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...

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...

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...

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...

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.

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 ...

Zirconia Oxygen Sensors and issues with Cold Junction Sensors

Please read the attached handout for more information. We no longer offer the Transistor style Cold junction. If using an older electronics (ZA8C/ZO21C/AV8G/AV8C) the unit will have to be replaced with a newer model and a K9470BG cold junction can b...

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...

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.

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. ...

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 ...

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.

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...

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 ...

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 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...

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.

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.

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.

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 ...

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...

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 ...

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...

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 ...

AV8C Maintenance and commissioning password

(KB-000-0409)

The password to access the maintenance and commissioning area is 77

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.

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...

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...

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.

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...

ZR402G I can't get past the password on my unit, or I have never set a password.

(KB-000-0431)

If you have set a password and have forgotten it you can use the password "MOON" to get into the configuration menu. Then you will be able to modify/view the password that is set in the unit. Note: if you have not set a password just...

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. ...

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

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, composition of the process liquid, maintenance activity taken, storage conditions, and sensor handling. To ...

Cleaning the GD40 Detector

(KB-000-0456)

Factory Recommended Method Use only 99% Isopropyl alcohol. Alcohol that is less than 99% will take longer to dry. Sometimes much longer. Denatured Alcohol is not 99% and should not be used. Clean with 99% isopropyl alcohol. Pour alcohol ...

Paring a GD402 Converter with a GD40 Detector

(KB-000-0457)

Whenever you are installing a gas density system, it is important to match the detector (GD40) to the analyzer (GD402). This applies to completely new installations, as well as when a GD40 detector is being used with a different analyzer. To match th...

HA400 Instruction Manual

(KB-000-0459)

See link

GD420/GD402 Alarm 10 - Calibration Alarm

(KB-000-0458)

If your analyzer has been up and running properly but when you try to calibrate you receive an "alm 10" code, then clean the detector and try again. See the below for cleaning instructions ...

How to wire a ZR22 to a ZR402G, with AC1 Autocal Panel

(KB-000-0424)

The wiring between the ZR402 Detector, the ZR22 Sensor, and the AC1 Autocal Panel is shown below. The Wiring between the ZR402G and the ZR22G must be installed in 2 separate conduits, one for the signal cable, and the other for the heate...

ZR22 Bolt Sizes

(KB-000-0420)

The ZR22 probes have the following bolt sizes Cell Bolts (4 ea.) - 8mm Housing bolts (4 ea.) - 10mm Heater strut retaining nut (K9470BA) - Custom thread. You may need the nut removal tool to loosen this nut: You can purcase it se...

Channel Cards for AV550 - I need a K9475MR

(KB-000-0412)

The part number you see on the channel card circuit board is not the part number for the channel card. It is the part number for the circuit board before any parts are installed. There are 2 versions on the channel card. If you look at ...

Where do I find documentation for the AV8C?

(KB-000-0411)

Here's a link to download the AV8G Manual.

AV550 I changed my channel card and now the channel will not power up

(KB-000-0414)

The AV550 automatically turns off the power to the channel card when it is removed. You have to either cycle power to the whole unit, or use the channel card power. To get to the channel card power menu hit the Setup Key (wrench). See below:&n...

AV550 Forgot password that is set.

(KB-000-0416)

You can use the password JAVAJAVA to get past the password screen. Make sure you go to the password menu change the password setting.

ZR22 Detector Troubleshooting

(KB-000-0419)

Meter Checks: Heater: 57-85Ω (typical is 62-67Ω) Typical failure is Open or shorted TC: if the probe is at room temperature - less than 3Ω, in the stack and hot less than 100Ω (it is a type K Thermocouple) Typical failure is ope...

I need to replace a ZO21D probe or a ZR22 probe with a /AV or /ZA on the end of the Model Number.

(KB-000-0418)

Yokogawa has been making Zirconia Oxygen Analyzers for over 30 years. The older O2 probes and analyzers used a transistor temperature sensor. The newer units use a PT1000 RTD. We discontinued the ZO21D probe and both the AV8G and ZA8C analyzers over ...

AV8C Channel reset code

(KB-000-0410)

You can use code 58 to reset a single AV8C channel. First scroll the display to the channel you would like to cycle, then enter code 58.

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...

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...

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...

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 ...

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 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...

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 ...

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 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 ...

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...

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...

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...

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...

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...

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 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 ...

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

(KB-000-0364)

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 support@us.yokogawa.com or call 800-524-7378.

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&...

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 ...

Can the FLXA202 or FLXA21 Converter using an analog sensor be changed to work with a SENCOM® sensor?

(KB-000-0354)

Yes, the input module can be changed in the Converter. See the FAQ: Which Input Module do I order for my FLXA21/202 analyzer? ...

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 ...

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...

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...

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...

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 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...

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...