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 .
The
"Calibration Table for Pipe Sizes 3…36 Inches" on page 14
provides calibration and operation data for most scheduled
pipe sizes 3…18 inches . For tee-mounted sensors, see the Metal Tee or the Plastic Tee user manual, available in the Resource
Library at
www.badgermeter.com
.
Description of Calibration Table Columns
Column
Description
Column 1
Nominal Pipe Size (NPS)
Column 2
Pipe outside diameter (O .D .) as defined by ASA B36 .10 and other standards
Column 3
Pipe inside diameter (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 connect
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 .
Calibration
Page 13
February 2018
SEN-UM-01635-EN-11