YSI Pro20 - Manual (Page 16)

EMERGENCY CONTRAST ADJUSTMENT
If necessary, there is an alternate method of adjusting the contrast. To adjust the
contrast, press and hold the menu key, then press the up arrow key to darken the
contrast or press the down arrow key to lighten the contrast.
SENSOR TYPE
The instrument’s Sensor Type must be configured for the sensor
installed. Failure to do this may result in damage not covered
under warranty. If you observe readings very close to 0 or
extremely high readings, i.e. 600%, your Sensor Type setting may
be set incorrectly.
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Sensor Type sets the type of oxygen sensor being used; either Polarographic
(black) or Galvanic (grey).
Use the up or down arrow keys to highlight Sensor Type, then press enter to
open a submenu. Highlight the sensor type corresponding to the sensor installed
on the cable and press enter to confirm. The enabled sensor type will have an ‘X’
in the box next to it. Use the down arrow key to highlight the ESC – Exit, then
press enter to save changes and to close the sensor submenu.
If using a ProBOD sensor/cable assembly, the sensor type should be set to
polarographic.
The Pro20 has two compatible sensors for use with a field cable:
Polarographic – This sensor has a black sensor body and is engraved with the
model number 2003. Polarographic will be abbreviated Polaro in the instrument.
Galvanic – This sensor has a grey sensor body and is engraved with the model
number 2002.
In terms of physical configuration, membrane material, and general performance,
YSI Professional Series Galvanic dissolved oxygen sensors are exactly like the
Professional Series Polarographic sensors. The advantage of using Galvanic
sensors is convenience. Galvanic sensors provide for an instant-on sensor without
the need for warm-up time but this affects the life of the sensor. Polarographic
sensors last longer and have a longer warranty but require a 5-15 minute warm-up
time before use or calibration.
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