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 gently.

Refillable sensor: Prior to measuring, open the reservoir stopper; close it after measuring. Check level of electrolyte in the sensor. If the sensor is going to be pressurized in an armature or housing, the pressure should be 0.5 bars above process pressure.

 

When installing follow the below guidelines:

The pH sensors we sell must be mounted with the tip pointed down at least 15 degrees, with 2 exceptions. Refer to Figure 1.

1. FU24 – These sensors have a Pressure Bellows that transmits the process pressure to the internal liquids inside the sensor. Because of this there is no air bubble in the pH sensor and it can be mounted in any direction. 
2. The Hamilton Polilyte Plus VP sensors can be mounted in any direction, including upside down.