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YSI IQ S ENSOR N ET NitraVis 70x IQ User Manual

Page 24

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Measuring / Operation

NitraVis 70x IQ

4 - 4

ba75950e02

11/2012

Sensor check (H2O dest.)

The characteristics of a sensor and thus the measured values provided

by it change in the course of time.
The reasons for this can be the aging of the sensor, or contamination

or mechanical damage of the sensor. Contamination or mechanical

damage in the area of the measuring chamber or on the measurement

windows affect the measured values.
In UV-VISspectroscopy, very small contamination that is not visible to

the eye can considerably affect the measured value.

The proper and thorough cleaning of the sensor is the basis for reliable

measurement data.

A

Sensor check (H2O dest.)

determines the condition of the UV-VIS

sensor. By checking the sensor with the aid of the

Sensor check (H2O

dest.)

you can rapidly see any changes of the sensor and whether it

needs to be cleaned or if any other actions have to be taken.
A

Sensor check (H2O dest.)

should be carried out twice per year at

regular intervals. An extraordinary

Sensor check (H2O dest.)

should be

carried out if you suspect that the sensor has been damaged such as

by mechanical shock, or if the measured values do not seem plausible.

Zero adjustment

While the

Sensor check (H2O dest.)

just determines the current state

of the sensor, a

Zero adjustment

can be used to compensate for

changes of the sensor. A zero adjustment can be required if, for

example, the

Sensor check (H2O dest.)

is not successful even after the

sensor was thoroughly cleaned.
The sensor should always be very thoroughly cleaned prior to a zero

adjustment.

If the

Zero adjustment

is not successful, the sensor is blocked for mea-

surement. A successful

Zero adjustment

is required for the determina-

tion of measured values.

Sensor check (standard)

Use the

Sensor check (standard)

to check the sensor with a standard

solution (see chapter 6 S

PARE

PARTS

,

MAINTENANCE

EQUIPMENT

,

ACCES

-

SORIES

). During the check, the recorded spectrum is compared to a

reference spectrum of the standard solution stored in the sensor.