User manual

Z11.0.0X.6C-13 page 2 of 4

General information about the oxygen sensors

I.) Lifetime:

At the end of life time the sensor signal drops relatively fast. The electrode evaluation in % therefore just can be

used for orientation. An evaluation of 70% does not mean that 70% of life time are remaining, but 70% of the ref-

erence signal are available, which happens normally at the end of life time.

Note: The electrode evaluation is updated by the instrument every time, when the calibration of the sensor was

performed successfully. (pleas also see the referring manual of the instrument)

The nominal life time can be shortened significantly by usage. Influencing factors are:

- Storage- / Operation temperature

- Humidity of measured gas: If permanently used with dry gases (technical gases, bottled gas) the life time de-

creases considerably.

It helps, if the sensor is brought to normal humid ambient air in measuring breaks (“flush” system with fresh air).

II.) Operating position:

The optimum operation position is with the sensor inlet pointing downwards, maximum differential pressure to am-

bient is 250 mbar.

III.) Measuring precision:

The measuring precision can be influenced by:

- Liquids at the sensor inlet. Rinse the inlet and dry with lint-free cloth.

Attention: avoid liquids of any kind at the contacts

- Gas and sensor temperature have to be at same level. Best precision, when calibrated at measuring tempera-

ture.

- Pressure fluctuations: The sensor is originally a partial pressure sensor, i.e. changes in the absolute pressure

are influencing the measuring result directly proportional. A pressure change of 1% will cause a additional

measuring error of 1%!

For optimum precision calibrate at the same conditions at which You want to measure.

Application areas for the sensors G... 370 and G... 380

GGO 370, GOO 370 (acidic electrolyte):

Specialized sensor for diving application e.g. measuring Nitrox.

Suitable for application with larger CO

concentration.

GGO 380, GOO 380 (basic electrolyte)

Sensor for low oxygen concentration e.g. controlled atmosphere.

For application without larger CO

concentration. *

: The sensors G__ 380 are designed to measure oxygen-concentration in air or other gases without larger CO

concentration. A higher CO

-concentration reduces the life-time of the sensor.

Short-time exposition at up to 10% CO

is not problematic (for example 15 minutes. up to 10 times per day) for the

sensor (exhaust measurings eg.) If there is measured more often with elevated CO

-concentration or at CO

concentrations above 10%, the exposition time has to be kept as short as possible and sufficient measuring

pauses should be made.

Note: If the sensor is not exposed to free air during measuring pauses, the connected tubes etc. have to be

flushed with clean air or nitrogen.