Download Operating instructions Acoustic, digital current meter OTT ADC

Specify the verticals
The number and position of the verticals are dependent on the geometric shape of
the measurement cross-section and the intended measurement and evaluation
method. The following rules apply according to EN – ISO 748:
Tab. Number of verticals
in relation to the waterway width
Please note: the minimum waterway width
to use an OTT ADC: 0.5 m!
Waterway width Number of verticals
in m
> 0 and < 0,5
3–4
> 0,5 and < 1
4–5
> 1 and < 3
5–8
> 3 and < 5
8 – 10
> 5 and < 10
10 – 20
> 10
> 20
The distances between verticals are generally smaller where water depth and flow
velocities change significantly. This affects above all the bank areas, vertical or
steep slopes, ledges in divided cross-sections and transitions from the main waterway bed to the foreland. Verticals should also be located at significant changes in
the profile of the waterway bed. With consistent bed gradient of the waterway
there is the possibility to reduce the number of verticals and to space them evenly
without being in conflict with the above requirements.
European standard EN ISO 748 recommends selecting verticals in such a way
that with large waterways a discharge segment defined by the vertical(s) represents less than 5% of the complete discharge where possible and a maximum of
10%. A sufficient number of verticals is thus a prerequisite.
With discharge measuring with the OTT ADC you can check the percentage proportion of the complete discharge for each segment: This is automatically calculated and shown on the display of the handheld unit at the end of the measurement.
See menu
Main menu [1/2]/Discharge Measuring/Start/.../Completed/Discharge Measuring/Details
6.2 Carrying out measurement
Requirements: The measuring equipment is complete and functioning, the station is
set up, sensor and, as required, handheld unit are attached to the rod, the sensor
is connected to the handheld unit.
6.2.1 Depth calibration
To determine the water and sensor depths, an absolute pressure cell is built into
the sensor body of the OTT ADC. To ensure correct measurement values, the pressure cell must be calibrated under the currently existing air pressure conditions.
23