Sondes
Section
2
YSI Incorporated
Drinking Water Monitoring Systems Operations Manual
2-39
•
After the warm-up time is complete, the readings just before and just after calibration are
displayed. When you press
Ente
r, the screen returns to the Free Chlorine Calibration menu.
2.7
2.7
2.7
2.7 TAKING READINGS
TAKING READINGS
TAKING READINGS
TAKING READINGS
After you have (1) enabled the sensors, (2) set the report to show the parameters that you want to see, and
(3) calibrated the sensors, you are now ready to take readings.
There are two basic approaches to sampling, Discrete and Unattended. Using discrete sampling, the sonde
is connected via a communication cable to a PC or terminal. The sampling frequency is likely to be rapid
(seconds) in order to obtain a representative sampling as you move from site to site. Readings will probably
be logged to several different files.
Unattended sampling is normally done with sondes that have internal batteries as do the 600DW-B and the
6920DW. The sampling frequency is likely to be longer (minutes). A sonde is typically deployed for days
or weeks at a time, and readings will be logged to a single file. The communication cable may be
disconnected and internal battery power used to operate the sonde. Alternatively, the sonde may connect
via SDI-12 communication to a data collection platform (DCP). Sondes without batteries need to be
connected to an external power source for unattended sampling.
NOTE: The 600DW-B and 6920DW are designed around the long-term, continuous monitoring of
drinking water if flow cell applications. Thus, for most studies data will either be stored at relatively
long sample intervals (5-60 minutes) to the internal memory of the sonde using the Unattended mode
or the sonde will be attached to a 6500 Process Monitor and the data will be output in 4-20 mA or
Modbus format and stored in a SCADA system or similar external logger. Thus, while the Discrete
sample mode may be required in some set-up and troubleshooting operations, most studies will be
done using the Unattended mode.
Select
1-Run
from the Main menu to begin taking readings or to set/verify the parameters required for a
study. There are two options in the Run menu as shown below.
===================================================================
Temp SpCond Sal DOsat Cl2 Depth pH NH4+ N NO3- N Turbid
C mS/cm ppt % mg/L feet mg/L mg/L NTU
-------------------------------------------------------------------
Stabilizing: 38
---------------Run setup---------------
1-Discrete sample 2-Unattended sample
Select option (0 for previous menu): 1
