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Tank height configuration: HyView user menu function 1.1.1 (HART® Function 2.1.1.1)
This function is usually either defined as true tank height or as factory configured probe length, L
2
if the former is not supplied by the customer in the order.
Why change the tank height?
Setting the distance in HyView user menu Function 1.1.1 (HART® Function 2.1.1.1) to the same value as L
2
avoids having a non-measurable zone underneath the
probe where the measurement on the display freezes. This means that when setting up a measurement scale as explained on the following page, the level at the end
of the probe will be taken as zero instead of the tank bottom.
How tank height affects measurement when either Level or Distance is measured
1
Tank height
2
Measurable height (factory configured probe length L
2
)
3
Non-measurable zone
4
With true tank height (1) set in Function 1.1.1.
5
With factory-configured probe length, L
2
, set in Function 1.1.1 of
the configuration page / user menu.
Example procedure 1:
to change true tank height (10000mm or 33 ft) to factory configured probe length, L
2
(9000mm or 29½ ft) , and
then save the new parameter. Refer to item 5 in the diagram above.
Step
Action
Data entered / value set
1
Connect to the instrument as described in section 5.1.
Tank status screen displayed (level reads 6750 mm)
2
Click on Measurement configuration menu
Configuration menu displayed
3
Click on the data set field for Function 1.1.1 Tank height
This field currently reads 10000 (mm)
4
Type in the new value
9000
5
Save the new configuration to disk by clicking on ‘Save to disk’ and
download it onto the VF04 2-wire using the ‘Send to’ button.
n/a
6
Press close to exit the configuration menu.
Tank status screen displayed (level now reads 5750 mm)
Dead zone configuration: HyView function 1.1.2 (HART
®
Function 2.1.1.4)
The top dead zone is the minimum measuring distance between the instrument flange facing (the reference point) and the product. The
various probes for the VF04 2-wire have differing top dead zones and these are given in section 3.2: Technical data of the probes
– Min.
measuring distance.
Why is configuration of the dead zone and detection delay important?
HyView user menu Function 1.1.2 (HART® Function 2.1.1.4): Dead zone
The instrument will not display measurements here – the reading is blocked on reaching this zone.
It should be noted that although the reading is frozen, the instrument will continue to follow the reflection and the HyView marker diagram will indicate “Tank full” in
this zone.
HyView user menu Function 1.5.1 (HART® Function 2.1.5.3): Detection delay
The “detection delay” function masks all signals (i.e. none are detected by the instrument) up to a defined distance from the flange face.
If the level continues to rise into the detection delay zone then HyView marker diagram display will indicate “Tank full” and “Level Lost”.
The detection delay zone value should be 100mm less than the dead zone value.
This is illustrated on the following page – the value in the box is the displayed value:
