Proline Promass 83 PROFIBUS DP/PA Commissioning
Endress+Hauser 113
Performing a zero point adjustment
1. Operate the system until operating conditions have settled.
2. Stop the flow (v = 0 m/s).
3. Check the shut-off valves for leaks.
4. Check that operating pressure is correct.
5. Using the local display, select the ZEROPOINT ADJUSTMENT function in the function matrix:
BASIC FUNCTION → PROCESS PARAMETER → ADJUSTMENT → ZERO POINT ADJUST.
6. When you press O or S you are automatically prompted to enter the access code if the
function matrix is still disabled. Enter the code (factory setting = 83).
7. Now use O or S to select START and confirm with F. Acknowledge the security prompt with
YES and confirm again with F. Zero point adjustment is now started.
– The message “ZEROPOINT ADJUST RUNNING” appears on the display for 30...60 seconds
while adjustment is in progress.
– If the flow in the pipe exceeds 0.1 m/s, the following error message appears on the display:
“ZERO ADJUST NOT POSSIBLE”.
– When the zero point adjustment completes, the “ZERO ADJUST.” function reappears on the
display.
8. Back to the HOME position:
– Press and hold down Esc key (X) for longer than three seconds or
– Repeatedly press and release the Esc key (X).
6.9.2 Density adjustment
It is advisable to perform a density adjustment when optimum measuring accuracy is required for
calculating density dependent values. The application may require a 1-point or 2-point density
adjustment.
1-point density adjustment (with one fluid):
This type of density adjustment is necessary under the following circumstances:
• The sensor does not measure exactly the density value that the user expects on the basis of
laboratory analyses.
• The fluid properties are outside the measuring points set at the factory, or the reference operating
conditions used to calibrate the measuring device.
• The system is used exclusively to measure a fluid’s density which must be registered to a high
degree of accuracy under constant conditions.
Example: Brix density measurement for apple juice.
2-point density adjustment (with two fluids):
This type of adjustment is always to be carried out if the measuring tubes have been mechanically
altered by, e.g. material build-up, abrasion or corrosion. In such cases, the resonant frequency of the
measuring tubes has been affected by these factors and is no longer compatible with the calibration
data set at the factory. The 2-point density adjustment takes these mechanically-based changes into
account and calculates new, adjusted calibration data.
Performing a 1-point or 2-point density adjustment
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Caution!
• On-site density adjustment can be performed only if the user has detailed knowledge of the fluid
density, obtained for example from detailed laboratory analyses.
• The target density value specified in this way must not deviate from the measured fluid density
by more than ±10%.
• An error in defining the target density affects all calculated density and volume functions.
• The 2-point density adjustment is only possible if both target density values are different from
each other by at least 0.2 kg/l. Otherwise the message “DENSITY ADJUST. ERROR” appears on
the display.
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