Hyquest Solutions Pty Ltd
Top Set Rod – Model: MagnaRod
© Copyright
- 4 -
Issue 1.03 5 Mar, 2013
Tajimi connector for
depth sensor
Banana sockets for
current meter
2. Product Overview
2.1
Overview
The
MagnaRod
can measure depth, and also indicate when a current meter is at 0.2, 0.4,
0.6… of the water depth.Any pulse type current meter can be connected, and after entering
the pulse to velocity equations, it can display the measured velocity directly. Velocity can be
either displayed in feet/sec (ft/sec) or metres/second (m/sec) and is chosen by the user in a
menu. When a measurement is being made, the
MagnaRod
counts contact closures,
measures elapsed time, and computes velocity to a precision of 0.01 ft/sec or 0.001 m/sec.
The velocity is computed based on the selection from up to 6 entered meter ratings, again
chosen from a menu. During a measurement, the
MagnaRod
sends through the Bluetooth
serial port the number of accumulating meter contact closures and elapsed time at 1-second
intervals.
An important operating feature of the
MagnaRod
is the ability to signal process each contact
closure. Contact closures from any type of meter are inherently noisy causing miscounting or
double counting. The
MagnaRod
samples the input signal from the connected meter and
examines the signal to determine if a contact closure has occurred and if successive signals
are of the same characteristics. The
MagnaRod
then determines contact closure conditions
and either counts the signal closure or eliminates the condition as a noise pulse and does not
count the signal. For cat’s whisker contacts, this becomes extremely important since cat’s
whisker contacts offer the poorest quality for marking and counting rotations.
The
MagnaRod
offers (2) modes of operation for a cat whisker type meter - FAST and
SLOW speed mode. FAST is selected for meter rotations >0.25 ft/sec while SLOW mode is
for velocities below 0.25ft/sec. To improve noise rejection, the sample rate of the input
signal at the SLOW speed mode (lower velocities) is 1/10 of the sampling rate that occurs
during FAST mode. This slower sampling rate improves performance for back rotations and
corroded whisker contacts at extremely low meter cup rotations. It is important to know that
the
MagnaRod
offers operational overlap at this 0.25 ft/sec velocity selection in either mode
and therefore it is not necessary for the operator to know precisely the velocity of water for
selecting either mode.
3. Installation
3.1
Hardware Connections
1. When the MagnaRod is clipped into the cradle,
the Tajimi connector must be screwed into the
mating part in the handle – this connects the sensor
used for depth measurement.
2. The current meter is connected through the 2
banana type sockets at the top of the MagnaRod.
