YOKOGAWA DOX8HS, User Manual, Page: 22 / 32

< 3. Installation, Piping and Wiring >
3-4
IM 19H1D2-01E
3.3 Installation
3.3.1 Selecting Measurement Point
Install the DOX8HS submersion type holder so that the DO70G/DO71/DO72 sensor and MLSS
sensor, dissolved oxygen sensor, is located at the measurement point.
Under normal conditions, select a measurement point that satisfies the following requirements.
• A location where a typical measured value of the solution to be measured can be obtained
Avoid locations where the solution to be measured is unevenly distributed since it will lead to
hunting for a measured value. Also avoid locations where air bubbles are generated.
• A location where the temperature and flow rate of the measured solution matches the usage
conditions of the sensor and holder
A fast flowing solution that contains sand may damage the sensor front end (membrane,
prism or sensor cap).
3.3.2 Selecting a Place of Installation for the DOX8HS
Submersion Type Holder
Sensors must be calibrated and maintained regularly.
Thus the DOX8HS submersion type holder should be installed in a location that satisfies the
following conditions.
• Space enough to allow calibration and maintenance near the measurement point
• A location where washing utility requirements are met. (submersion type holder with
washing device.)
CAUTION
Installation Location of Holders
The holder should be used in a place that is as vibration free as possible.
Using the holder in a place where it is affected by vibration, may result in damage to the holder.
(Guide Pipe, Submersion Type, etc)
3.3.3 Securing DOX8HS Submersion Type Holder
The DOX8HS submersion type holder is normally secured to 2-inch pipe (outer diameter 60.5
mm) using a mounting bracket. The pipe shall be placed vertically.
The submersion type holder must be removed to allow calibration and maintenance.
Therefore install the holder in a location where removal is easy to perform.
3.3.4 Installing DOX8HS Submersion Type Holder
(1) Secure the submersion type holder with the installed sensor (see “3.1 Installation procedure
for the DO71 sensor to DOX8HS”) to a stanchion (pipe for mounting the holder).
NOTE
Be sure not to soil or expose the prepared end of the sensor cable during the work
When the submersion type holder has been secured, check that,
• The sensor front end is in a location where it is not likely to collect air bubbles.
•
The sensor front end is immersed in the solution regardless of fluctuations in the solution level.
(2) Connect the sensor cable to the converter (or terminal box). For details, refer to supplied
user’s manual.