Calibration Without Pressure; Zero Point Calibration; Span Calibration - Burkert 8326 Manuel Utilisateur

5.4

Calibration without Pressure

Determine the current reference values for the zero point and the span to be entered
in the transmitter before calibration. This is done as follows:

5.4.1 Zero Point Calibration

• Determine the hydrostatic pressure of the liquid's surface that meets the zero point.
• Adjust this pressure in proportion to the sensor's nominal pressure range.
• Multiply this proportion by 16 mA and add 4 mA to the result.
This produces the calculated current (value I
and used to programm the zero point (0%).
Example:
A pressure transducer with 0 ... 400 mbar (nominal pressure) needs to be pro-
grammed.The liquid's surface (with a density of 1) is 1 m above the diaphragm at the
zero point producing a pressure of 100 mbar.
I
=
calc
This means that the device's current value must be set to 8 mA when performing a dry
(empty) calibration.
Calibration Value
calc
Calibration of zero point, without display, without pressure

5.4.2 Span Calibration

• Determine the hydrostatic pressure of the liquid's surface, which corresponds to the
span end-point.
• Calculate the difference of the pressure value between span end-point and zero
point and divide this difference by the nominal pressure range of the sensor.
• Multiply this proportion by 16 mA and add 4 mA to the result.
This produces the calculated current (value I
and used to program the span end-point (100%).
The measurement range between zero point and span end-point will be stored as
span.
Subject to technical changes without notice.
GB-17
Operation of Devices without Displays
Zero point pressure (0%) 100 mbar
------------------------------------------------------------------------------------------------ 16 mA
Sensors nominal pressure 400 mbar
Pressure Transmitter 8326
), which is entered in the transmitter
calc
⋅
+ 4 mA
Set
Value
... to I
meas
... to I
meas
), which is entered in the transmitter
calc
= 8 mA
Calibration Value
= I
calc
= I
calc