Double Conical Tank Strapping Table Adjustment

Double Conical Tank Strapping Table Adjustment

Adjust a strapping table when the probe and transmitter are mounted a considerable distance from the deepest part of the tank.

Overview

When This Applies

This solution is only required when the customer wants to see 2LO on the display instead of a volume when the probe and transmitter are mounted a considerable distance away from the deepest part of the tank.

In many cases where the probe is mounted near the deepest part of the tank, the display will still show 2LO. No strapping table changes are required for this situation.

The strapping table adjustment depends on accurate measurement of the distance from the top of the tank to the bottom directly under the probe. This measurement is used to create the new strapping table.

Diagram of probe distance from the deepest part of the tank

Procedure

Strapping Table Adjustment Procedure

  • 1

    Create a New Strapping Table

    Create a strapping table with a depth of the same distance measured at the probe. For this example, the deepest part of the tank is 84", the depth at the probe is 80" — create an 80" deep strapping table. Ensure that the depth is measured to the top of the tank and not to the top of the collar or riser.

    Creating an 80 inch deep strapping table
  • 2

    Record the Original Settings

    Record the following from the original strapping table:

    • Probe type
    • Detection mode
    • Depth and volume units
    • Offset Measurement
    • Spill alarm level and Reset method
    • HH alarm volume
    • Display Settings
    • 4-20mA settings
  • 3

    Calculate the Difference

    Calculate the difference between the deepest part of the tank and the probe location. For this example, 84" − 80" = 4".

  • 4

    Note the Starting Volume

    On the tank's original strapping table, note the volume at 4" (for this example). The volume of 528 is where the new strapping table will start at 0".

    Original strapping table volume at 4 inches
  • 5

    Note the Maximum Volume

    Note the maximum volume of the tank according to the original strapping table. For this example, it is the volume of 31390 at 84" on the strapping table.

    Original strapping table maximum volume at 84 inches
  • 6

    Start the New Table

    Create a strapping table beginning with 0" and the volume at 4" from the original strapping table. For this example, start the table with 0" and 528.

    New strapping table starting entry
  • 7

    Finish the New Table

    Continue to build the new strapping table with the maximum volume at 80". For this example, the table ends at 80" and 31390.

    New strapping table ending entry
  • 8

    Finish and Save

    Enter the Offset Measurement — this is the newly measured offset at the probe position, and may differ from the original strapping table. Use the original offset if a new measurement is unavailable. For this example, the Offset Measurement is 1.44". Complete the new strapping table entries, then save the new strapping table with a descriptive name.

Result

The New Strapping Table

New strapping table, top entries
New strapping table, remaining entries