YSI 85 - Manual (Page 5)

YSI, Incorporated Model 85 1
SECTION 1 INTRODUCTION
The YSI Model 85 Handheld Dissolved Oxygen, Conductivity, Salinity and Temperature System is
a rugged, micro-processor based, digital meter with an attached YSI combination conductivity and
dissolved oxygen probe.
The YSI Model 85 is designed for use in field, lab, and process control applications as well as for
environmental, aquaculture, and industrial uses. The Model 85 is available with cable lengths of
either 10, 25, 50 or 100 feet. The body of the probe has been manufactured with stainless steel to add
rugged durability and sinking weight. The probe also utilizes our easy to install cap membranes for
measuring dissolved oxygen.
The YSI Model 85 probe is a non-detachable, combination sensor designed specifically for the YSI
Model 85 Handheld System. The conductivity portion is a four-electrode cell with a cell constant of
5.0/cm
±4%. The dissolved oxygen portion is a polargraphic Clark type sensor.
The Model 85’s microprocessor allows the system to be easily calibrated for dissolved oxygen or
conductivity with the press of a few buttons. Additionally, the microprocessor performs a self-
diagnostic routine each time the instrument is turned on. The self-diagnostic routine provides you
with useful information about the conductivity cell constant and function of the instrument circuitry.
The system simultaneously displays temperature (in °C), along with one of the following
parameters: dissolved oxygen in either mg/L (milligrams per liter) or % air saturation; conductivity;
temperature compensated conductivity; (in
µS/cm or mS/cm), and salinity (in parts per thousand
{ppt}).
The system requires only a single calibration regardless of which dissolved oxygen display you use.
The calibration of conductivity is not required but is available. A single calibration will adjust the
instrument, regardless if you are reading conductivity or temperature compensated conductivity.
You can switch between all of these parameters with the push of a single key.
A calibration\storage chamber is built into the instrument case. A small sponge in the chamber can
be moistened to provide a water saturated air environment that is ideal for air calibration of the
dissolved oxygen probe. This chamber also provides a convenient place to store the probe when the
system is not in use, and provides protection for the electrodes within the conductivity probe. The
Model 85 case is also waterproof (rated to IP65). You can operate your Model 85 in the rain without
damage to the instrument.
Six AA-size alkaline batteries power the instrument. A new set of alkaline batteries will provide
approximately 100 hours of continuous operation. When batteries need to be replaced, the LCD will
display a “LO BAT” message.