KAPTOR
MINI
–
User Manual
–
V0.1 - pg.46
✓
Integrated: read directly by the doppler sensor via
a hydrostatic cell;
✓
External: read by an additional sensor connected to
analog input 1. The value must be expressed in
millimeters (the configuration of the sensor must
be made in the appropriate analog menu);
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Combined: allows you to perform the measurement
in both previous modes based on a threshold level.
Threshold level combined mode
: indicates the threshold,
expressed in millimeters from the bottom, for determining
the level in the case of a
“
combined
”
level type. Below this
threshold the measurement is carried out with the
integrated level of the Doppler, above the threshold the
measurement is carried out with the external sensor
connected to AN1.
Sensor type
: you can select the type of sensor in use:
✓
Open canal: doppler wedge sensor to be positioned
on the bottom of the channel;
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Full pipe: insertion doppler sensor to be mounted
on a special sleeve (refer to the specific sensor
manual for further information).
Critical level
: level below which the speed is no longer read
by the sensor. The minimum critical level is 40 mm as the
sensor would be furious from the water. However, a higher
critical level can be used.
Critical level is the level below which the sensor is no longer
able to correctly measure the speed due to the geometry of
the sensor (height 4 cm) and the hydraulic conditions.
The flow below the critical level is calculated using the
reading of the only level by applying the Strickler algorithm,
if enabled, otherwise it is set to 0.
Enable Strickler under critical level
: by enabling the option,
the flow rate below the critical level is calculated with the
Strickler formula according to the set coefficient.
𝑄 = 𝐾
𝑠
∙ 𝑅
𝐻
2
3
∙ 𝑖
𝑓
1
2
∙ 𝐴
Where:
✓
Q is flow rate (m
3
/s);
✓
Ks is the Strickler roughness coefficient (m
1/3
/s),
depending on the nature of the pipe/riverbed material;
✓
R
H
is hydraulic radius (m) defined as a correlation
between wet area and wet perimeter. It is automatically
calculated;
✓
I
f
is the bottom slope (m/m)