YSI 85 - Manual (Page 22)

Making Measurements Section 7
YSI, Incorporated Model 85 18
300.1
µS
23.4
o
C
If the instrument is reading Specific
Conductance the large numbers on the display
will be followed by either a
µS or an mS.
Additionally the small portion of the display will
show the
o
C flashing on and off.
If the instrument is reading Conductivity (not
temperature compensated) the large numbers on
the display will be followed by either a
µS or an
mS. Additionally the small portion of the display
will show the
o
C NOT flashing.
If the instrument is reading Dissolved Oxygen the large numbers on the display will be followed by
either a mg/L or %. It is important to remember that the dissolved oxygen probe is stirring
dependent. This is due to the consumption of oxygen at the sensor tip during measurement. When
taking dissolved oxygen measurements the probe must be moved through the sample at a rate of 1
foot per second to provide adequate stirring.
If the instrument is reading Salinity the large numbers on the display will be followed by a ppt.
7.3 AUTORANGING & RANGE SEARCHING
The YSI Model 85 is an autoranging instrument. This means that regardless of the conductivity or
salinity of the solution (within the specifications of the instrument) all you need to do to get the most
accurate reading is to put the probe in the sample. This feature makes the Model 85 as simple as
possible to operate.
When you first place the Model 85 probe into a sample or calibration solution, and again when you
first remove the probe the instrument will go into a range search mode that may take as long as 5
seconds. During some range searches the instrument display will flash
rANG to indicate its
movement from one range to another. The length of the range search depends on the number of
ranges that must be searched in order to find the correct range for the sample. During the range
search, the instrument will appear to freeze on a given reading for a few seconds then, once the
range is located, will pinpoint the exact reading on the display. The display may also switch to 00.0
for a second or two during a range search before it selects the proper range.
7.4 THE BACKLIGHT
At times it may be necessary to take measurements with the Model 85 in dark or poorly lit areas. To
help in this situation, the Model 85 comes equipped with a backlight that will illuminate the display
so that it can be easily read. To activate the backlight, press and hold the LIGHT button. The
display will remain lit as long as the button is depressed. When you release it, the light goes out to
preserve battery life.