8
2. Scuba basics
Royal Eijkelkamp is the only major multiprobe manufacturer that provides a three-year warranty that covers all
sensors, including pH and DO
.
2.1 Deployment specifications
The Scuba can be used in natural water up to 50 degrees C and 200 meters deep, except that ISE’s are rated to
10 meters deep, and TDG sensors and low-range depth should go no deeper than 25 meters.
2.2 Scuba control software flow chart
Please see the first page in Section 3.
2.3 The Scuba has four basic applications
1
Manual data collection, also known as profiling, surveying, site-to-site measurements, etc., means that the
user is present at the monitoring site and uses a data display for observing measurements. This allows the
user to make data-based decisions in the field in real-time, and lets the user visit multiple monitoring sites
in one day. The data display can be a laptop, Amphibian, or almost any tablet or smartphone. The user
makes note of measurements either with pen and paper or, preferably, by using the Scuba’s snapshot or
automatic snapshot features. You might “snapshot” a series of measurements in one or more lakes or
streams during the day, and then download the data to your desktop PC that evening (see 3.3, 5.1).
2
Unattended logging means that the user has set the multiprobe into its logging mode, deployed the
multiprobe in the proper location in the water, and then left the site. The Scuba can run for weeks at a
time with cable-supplied power or an optional Scuba integral battery pack. You can, for instance, set the
instrument to take a set of readings every half-hour, anchor it in an estuary, and return after two weeks to
retrieve the instrument and download the data to a PC, laptop, or Android device.
3
Telemetry relay means that the user has connected the multiprobe to a telemetry device, deployed the
Scuba in the proper location in the water, and then left the site. A cable connects the multiprobe to the
telemetry system. The telemetry device uses satellite or cell-phone communication to periodically report
data collected by the multiprobe to the user’s office PC or to a proprietary web page. In many telemetry
systems, the user can also contact the multiprobe and request transmission of the most recent data.
Telemetry relay allows the user to collect data all night and all day for weeks without being present at the
monitoring site and allows the user remote access to those data at any time. Telemetry is helpful in
deciding when a trip to the field for multiprobe calibration or maintenance is necessary. Telemetry is also
ideal in locations for which access is dangerous or expensive.
On-line monitoring, also known as process-control monitoring, means that the multiprobe is connected to
a PLC, SCADA system, etc. An example is monitoring the input to a water-treatment plant for salinity or
chlorophyll. On-line monitoring allows the user to make water-quality-based decisions in real-time. The
Scuba is particularly effective in this application when more than one parameter is used in the control
loop.
