YSI 600DW-B, Руководство пользователя

Страница: 289 / 298

Frequently Asked Questions About YSI Drinking Water Systems Appendix H
YSI Incorporated Drinking Water Monitoring Systems Operations Manual H-3
•
A water tap with a valve or regulator to control flow and a fitting to allow the attachment of an inlet hose
from the tap to the YSI flow cell.
•
A drain to collect and dispose of the flow cell effluent
•
Hardware to securely mount the sonde. This can be as simple as a hook on the wall to attach to the sonde
bail or a horizontal binding strap to attach a floor or table mounted sonde to a wall or a frame.
•
A site at which the water inlet and outlet will not freeze under winter conditions.
Do I need to have AC power at the deployment site?
No – the DW sondes can both operate from internal battery power for stand-alone studies in which data is logged to the
sonde memory and then uploaded periodically for analysis of previous events. However, if you wish to see your data
in real-time through the use of a SCADA system after processing the data via YSI 6500 Process Monitor between the
sonde and the SCADA, then AC power will be required at the site. In addition, if you wish to attach the sonde to a
DCP (such as the YSI 6200 or YSI EcoNet system), then the use of AC power greatly facilitates the setup. Finally,
even for stand-alone deployments, the use of the YSI 6038 or 6651 power supplies saves the internal batteries and
therefore is recommended if there is AC power at the site.
I would like to install a drinking water monitoring device directly into a pipe and avoid the need for a drain
line? Can I do this with the YSI Drinking Water Sondes?
At the present time, there is no mechanism to insert standard YSI Drinking Water Sondes into a pressurized water
distribution system. Depending on market requirements, this type of application might be supported in the future, but,
for now, the answer is “No”.
I would like to install a drinking water sonde in my water storage tank by simply suspending it from a support
into the tank? Can I do this with the YSI Drinking Water Sondes?
The sondes and sensors were not designed for this application, but might still provide valuable information under these
conditions as long as a limitation with regard to the free chlorine sensor is recognized by the user. This limitation is
that the free chlorine sensor is NOT flow independent (see below for more information). The flow dependence is not
an issue in side-stream (flow cell) applications where the flow is greater than 500 mL per minute and is relatively
constant. However, the varying flow conditions which exist directly in water storage tanks (from completely stagnant
to significant flow during filling and emptying operations) will result in significant inaccuracies in the free chlorine
data. These errors could be up to 30 % of the reading depending on the time of calibration, in addition to the +/- 0.15
mg/L accuracy specification associated with the sensor when used in flowing water. In addition, if the chlorine
content of the tank is stratified, obtaining a representative sample for calibration my also be difficult and would result
in an additional error component. Users with tank applications should be prepared for levels of error significantly
higher than those specified for flow cell applications if they suspend their drinking water sondes directly in storage
tanks.
INTERFACING TO YSI DRINKING WATER SONDES
What modes of operation can be used with the YSI Drinking Water Sondes?
As described below, the YSI DW sondes are designed to operate in a variety of modes while acquiring long term
continuous data.
•
Stand-alone – In this mode the sonde is set up and calibrated off line (except for free chlorine, see below)
and then installed at the site in the appropriate flow cell with the sonde powered by internal batteries. An
Unattended study is then begun at a suitable interval (usually 5-15 minutes) and data is logged to internal
memory for the length of the study. The data can be uploaded periodically for after-the-fact viewing using
either a PC or a YSI 650 Display/Logger.