Badger Meter Irrigation Sensors - 1/2 and larger" - Manual (Page 9)

Installation & Operation Manual
CALIBRATION
Badger Meter sensors use unique K and Offset numbers
for calibration. These numbers are derived from calibration
runs using NIST traceable instruments. Using both a K and
an Offset number provides higher accuracy than using a K
(pulse/gal) factor alone. K and Offset numbers for each tee
configuration are listed in the following tables.
Calibration Tables
The table on pages 12 and 13 provides calibration and
operation data for most scheduled pipe sizes from 3
inches through 18 inches. For tee-mounted sensors, see
either Metal Tee (Manual Number 872021), or (Plastic Tee
Manual Number 872022).
Description of Column Information for
Pipe Sizes 3 inches through 36 inches
Column 1 Nominal Pipe Size
Column 2 Pipe O.D. as defined by
ASA B36.10 and other
standards
Column 3 Pipe I.D. as defined by
ASA B36.10 and other
standards
Columns 4 and 5 The K value and Offset
that should be used in our
frequency equation:
Freq=
Gpm
K
- Offset
This equation describes
the frequency of the
output signal of all Badger
Meter flow sensors.
By substituting the
appropriate K and Offset
values from the table, the
sensor’s output frequency
can be calculated for each
pipe size. This information
is required when
calibrating an output
board or when using the
raw sensor data as direct
output to interface with a
device that is not a Badger
Meter product.
Column 6 This column indicates the
suggested flow range of
sensors in each pipe size.
Badger Meter sensors
will operate both above
and below the indicated
flow rates. However, good
design practice dictates
the use of this range for
best performance.
Sensors should be sized for
flow rather than pipe size.
To prevent disturbances
to the flow profile, always
conntect the sensor
tee to the pipe nipples
measuring at least ten pipe
diameters in length on
the downstream (delivery)
side before making the
transition in pipe size.
Page 9 August 2012