FU20-03-T1-NPT/FU20-05-T1-NPT/FU20-10-T1-NPT/FU20-20-T1-NPT使用方法

FU20-03-T1-NPT、FU20-05-T1-NPT、FU20-10-T1-NPT、FU20-20-T1-NPT

User's Manual
Model FU20 and FU25 pH, Redox and Temperature sensorsUser's Manual

1. Introduction
1-1. Description
The wide body sensor gives you a simple solution to a common measurement.With one wide body sensor pH, redox and temperature can be measured.The sensor is directly fitted to the process by the industry standard threaded connection.In addition to that, the FU25 has a twist-lock quick fix and release construction without the need for special equipment.
The especially designed fixed cable has integrated for the pH sensor, reference sensor,temperature sensor, shielding and liquid earth. The cable is prefinished to make connection to any industrial pH instrument as simple as possible.
1-2. Warranty
Yokogawa Electric Co. warrants that the goods delivered are made from new materials to the best workmanship available. Malfunction of any of the delivered goods or parts ofit, can only lead to replacement of the damaged parts. No claims can be made to damages or accidents resulting from the use of the goods.No claims can be made to the expected or performance of the goods under any circumstances.
Damaged goods or parts should be sent to the local service organisation for warranty claim purposes.
Yokogawa has the right to deny warranty claims after investigation of the data and materials.
 

Contents
1. Introduction ........................................................................................................ 1
1-1. Description .......................................................................................................... 1
1-2. Warranty .............................................................................................................. 1
2. Specifications ...................................................................................................... 2
2-1. Model- and suffix codes FU20 ........................................................................... 2
2-2. Model- and suffix codes FU25 ........................................................................... 2
3. Installation .......................................................................................................... 3
3-1. Unpacking and checking ..................................................................................... 3
3-2. Installation site .................................................................................................... 3
3-3. Installation method .............................................................................................. 3
3-4. Assembly of FU25 adapter, taping the thread .................................................... 4
3-5. Installation examples ........................................................................................... 4
3-6. Preparing the sensor for use................................................................................ 5
3-7. Mounting the sensor into the process ................................................................. 6
3-8. Wiring instructions .............................................................................................. 6
3-9. Wiring diagram ................................................................................................... 7
3-10. Dimensions .......................................................................................................... 8
4. Maintenance...................................................................................................... 10
4-1. General .............................................................................................................. 10
4-2. Cleaning............................................................................................................. 10
4-3. Calibration ......................................................................................................... 11
4-3-1 General calibration procedure ................................................................... 11
4-4. Replacing the electrode ..................................................................................... 12

1. Introduction
1-1. Description
The wide body sensor gives you a simple solution to a common measurement.
With one wide body sensor pH, redox and temperature can be measured.
The sensor is directly fitted to the process by the industry standard threaded connection.
In addition to that, the FU25 has a twist-lock quick fix and release construction without
the need for special equipment.
The especially designed fixed cable has integrated for the pH sensor, reference sensor,
temperature sensor, shielding and liquid earth. The cable is prefinished to make
connection to any industrial pH instrument as simple as possible.
1-2. Warranty
Yokogawa Electric Co. warrants that the goods delivered are made from new materials
to the best workmanship available. Malfunction of any of the delivered goods or parts of
it, can only lead to replacement of the damaged parts. No claims can be made to
damages or accidents resulting from the use of the goods.
No claims can be made to the expected or performance of the goods under any
circumstances.

Damaged goods or parts should be sent to the local service organisation for warranty
claim purposes.
Yokogawa has the right to deny warranty claims after investigation of the data and
materials.

2、Specifications
2-1. Model- and suffix codes FU203. 3、Installation
3-1. Unpacking and checking
When you receive the FU20 or FU25 sensor it is packed in a cardboard box. Open the
box and check that the modelcode on the fitting is the same as on the packing list. Also
check that it is supplied with the option you ordered. The conductivity fitting adapter for
FU20 and the NPT/BSP twist lock adapters for FU25 are delivered as an option. If you
have any problems or questions, contact the nearest Yokogawa Engineering Service or
Sales organisation for assistance.
The FU20 or FU25 sensor has an identification number on the cable with the full
modelcode and a serialnumber.
3-2. Installation site
The FU20 sensor is intended to be used for in-line or by-pass pH measurement. The
FU25 is delivered with an optional adapter-piece, so it can be retracted from its position
by simply turning the complete sensor anticlockwise by hand.
The location can be at the bottom of an immersion pipe or directly into large diameter
pipe-line or vessel.
Several examples are given in the drawings on the next page.
Installation in a bend of a pipe-line is a good measurement position.
When inserting the FU20 or FU25 sensor in a perpendicular position to the process flow,
the flow velocity will put a mechanical force on the probe. Take care that this force is
not too large. It is recommended to have the FU20 or FU25 sensor positioned at a 45º
angle into the process stream.

 3-3. Installation method
It is important to have the point of measurement in a location that truly representing the
process composition. Check whether the specifications of the sensor fulfil the maximum
occurring process conditions.
The FU20 has a 3/4"NPT or ISO 7/1-R3/4 connection. The FU25 has a 1"NPT or ISO 7/
1-R1 connection.
Check that you received the correct type. The FU20 comes complete as one part, the
FU25 comes with a twist-lock adapter. Install the fitting at a convenient location
accessible for maintenance and calibration.
For maintenance or calibration the probe will need a space of about 0.5 meter for
retraction. The sensor can be mounted in any position to the horizon; with the tip
pointing downward, sideways or even upward.
To prevent the loss of process liquid when the sensor is removed, it is advised to either
drain or stop the flow in the process-line where the sensor is mounted.

3-4. Assembly of FU25 adapter, taping the thread
When the adapter is ordered with the FU25, it should be mounted to the measuring
position first. When the adapter is in place, the sensor can be put into the adapter by
turning the twist-lock coupling clockwise （see drawings on this sheet）.
The FU20 and FU25 are equipped with a threaded connection. A gas or watertight
sealing can only be achieved by taping the male threaded part with PTFE tape. No
further instruction or description is given in this manual.
3-5. Installation examples

3-6. Preparing the sensor for use
Take a new sensor from the box （model FU20 or FU25）. Take it out and remove the
“wet” pocket.

3-7. Mounting the sensor into the process
Find a suitable measuring point to connect the sensor. Prepare the male thread with
PTFE-tape and mount the sensor. Mount and connect the cable to the transmitter.
IMPORTANT NOTICE:
Before mounting the sensor, it should be calibrated. The calibration procedure is
normally described in the instruction manual of the pH transmitter, but a general guide is
given in chapter 4-2.
Mount the adapter of the FU25 into the threaded pipe using a screw-driver as shown in
the drawing below.

3-8. Wiring instructions
The cable used in the FU20 or FU25 sensor or prepared for easy connection to pH
transmitters.
The numbering of the wires is according to the standard terminal numbering of
Yokogawa pH transmitters. For redox measurement not all numbers are correct. Look at
the connection diagram and short terminals 13 and 14.
Remark:
To make full use of the capibilities of the combined pH/Redox and temperature sensor,
the cooperation with Yokogawa pH transmitters is preferred.

3-9. Wiring diagram

3-10. Dimensions

4. Maintenance
4-1. General
Before the sensor can be serviced, it should be physically separated from the pro
The FU20 or FU25 sensor can be taken from its measuring position by following
procedure described below.
4-2. Cleaning
Separate the sensor from the process according to the following procedure.
- Turn the sensor anti-clockwise
- Take out the sensor
- Spray with water or detergent
- Use a soft brush to remove dirt
- Check the sensor visually for damages
- Calibrate the sensor （See chapter 4-2）
- Mount the sensor again

Remarks:
- Use new PTFE tape on the threaded parts.
- Take care to avoid torsion of the cable by first turning it anticlockwise before
tightening the process connection.
- When the sensitivity of the sensor has decreased or the response has slowed down, the
electrode needs cleaning.
- If cleaning with hot water is not sufficient, more aggressive water based agents should
be used.
Examples:
1. Deposits of items, hydroxides or carbonates can be removed by immersing the
electrode in a solution containing diluted hydrochloric acid. Afterwards rinse with
water.
2. Deposits of oil and fat can be removed with hot water in conjunction with a
detergent. When the results are unsatisfactory a mild （carbonate based） abrasive can
be used.
3. Protein （alduminous） deposits should removed with a protein enzymatic solution. For
instance a solution containing 8.5 ml concentrated hydrochloric acid and 10 gram
pepsin in 1 litre water will do.

Note:
Avoid using non-polar solvents like tri-chloro ethylene, toluene or hexane.
Cleaning with iso-propanol or methanol is acceptable. The non-polar solvents will break
up the gel-layer on the glass bulb and afterwards the electrode needs to remain soaked in
water for at least 12 hours before functioning normally again.
The PTFE diaphragm of the sensor can sometimes be regenerated by putting it in hot
（60 to 80 ºC） 3 molar Potassium Nitrate （KNO3
） solution and letting it cool to room
temperature.
After cleaning the probe is re-inserted into the process by following the reverse
procedure.
4-3. Calibration
It is recommended to start calibration with a clean electrode. Always calibrate a new
electrode.
With the electrode connected to the transmitter a calibration can take place.
Check the appropriate chapters in the manual of the pH transmitter for details.
- Turn the sensor anti-clockwise
- Pull out the sensor
4-3-1 General calibration procedure
To calibrate a pH measurement two buffer solutions with known pH values are needed.
It is recommended that one buffer solution has a value as near to pH 7 as possible （e.g.
buffer pH 6.98）. Depending on the value to be measured the second buffer solution
should either be in the acidic or caustic area.
Normally the IEC buffers pH 4.01 or 9.22 are used.
Very generally a calibration procedure goes like this:

1. Clean the electrode,
2. Rinse it with water,
3. Immerse it in the first buffer （near pH 7）,
4. Adjust the transmitter reading to the known volume with the asymmetry setting,
5. Rinse the electrode with water,
6. Immerse it in the second buffer （near pH 4 or 9）,
7. Adjust the transmitter reading to the known value with the slope setting,
8. Rinse with water again.
During calibration the temperature compensation should be active. It is advised to
calibrate with buffers at a temperature near the process temperature.
After calibration the probe is replaced by following the reverse procedure or the
mounting instruction.

4-4. Replacing the electrode
Start with removing the electrode by following the procedure described below:
- Turn the sensor anti-clockwise
- Pull out the sensor
Now the electrode can be exchanged for a new one. Go to chapter 3-2 for preparation of
the new electrode.
Remark:
The drawing shows to position of the sealing o-ring on the outside. Exchange it when
renewing the electrode.

User's
Manual
Manual
Changes MODEL FU20 and FU25
pH, Redox and Temperature sensors
Thank you for selecting MODEL FU20 and FU25 pH, Redox and Temperature sensors.
The User's Manual IM 12B07K02-01E 1st edition supplied with this product has been amended as follows, please make a note
in your copy.
-Page 1, Some revision of sensor external view.
-Page 2, Section 2-1, "Model- and suffix codes FU20", option code of "/NAG" for the FU20 deleted.
-Page 7, Section 3-9, "Wiring diagram":
The actual colors of core wires of sensor cables have been changed. Please conduct wiring according only to the marking
numbers attached onto the core wires as referring to the attached revised page, and disregard the color codes of the core wires.
-Page 8, Section 3-10, "Dimensions":
The external dimensions of the FU20 have been changed in part. Please replace the drawings on page 8 with revised ones
attached hereto, and use the revised drawings for installation.