Optex SE-pH-D Instruction Manual page 7

・ The electrode has an expiration date. Use in order
from the oldest electrode. The date of manufacture
is indicated on the sensor body (last two digits of
the year + two digits of the week number)
・ When the calibration solution (standard solution)
is used after immersion in the measurement
water, the influence of the previous measurement
water can be minimized by cleaning the sensor
in advance. Use clean, non-abrasive paper or
a soft cloth for cleaning. Do not use a brush to
clean the glass part of the electrode.
・ Rinsing before measuring the measurement water or
calibration solution (standard solution) minimizes the influence
of the previous measurement water.
・ It takes time for the measurement value to stabilize. It depends
on the solution but in general, it takes 10 to 15 seconds to
obtain the measurement value with a new pH electrode. The
ORP electrode may take longer to stabilize.
・ The pH electrode deteriorates over time. As deterioration
progresses, the span becomes shorter and the response speed
Caution
decreases. This effect is best seen in a 2-point calibration.
・ If the sensor cannot correct the measurement value or the response
speed is too slow, the electrode needs to be replaced. The
frequency of electrode replacement varies depending on the usage
conditions. Electrodes that measure water at high temperature with
very high or low pH values have a shorter lifetime than those that
measure water at room temperature with neutral pH values.
・ If a film is formed on the surface of the electrode, the
measurement surface of the electrode does not properly contact
with the measurement water, causing the same adverse effects
as aging degradation of the electrode. Check to see if a film has
been formed on the glass surface before replacing the electrode.
If a film is formed, refer to "Cleaning tips" P.53 to remove it.
・ Sensor measurement values are affected by temperature.
The output of the electrode varies with temperature. For the pH
electrode, the measurement value can be adjusted manually or
automatically (There is no automatic adjustment to reflect the
temperature effect on the ORP measurement value). Also, the
actual pH or ORP value is temperature dependent, regardless of
the electrode being measured or the temperature compensation.
Date of
manufacture
7