Procon Forcecal email Procon Engineering
Dedicated Force Calibration Technique for Tanks, Vessels and Silos
ForceCal Benefits System Overview Methods Traceability ForceCal DVD Contact Us Procon Website
ForceCal Methods

There are two well proven Force Cal methods known as PUSH DOWN and LIFT UP. The choice depends on vessel design, site conditions and production requirements. If the vessel is full of product, the “Lift Up” method is used. If the vessel is empty, the “Push Down” method is used. Where possible, for optimum calibration flexibility, we recommend the fitting of “Dual Option” test rig brackets. These allow the vessel to be calibrated under any site condition (third method).

FIRST METHOD -PUSH DOWN

The on-site set up and use of the Force Cal “Push Down” method is carried out as follows:

Firstly before entering the work area, the necessary work permits are obtained.

  • If required the Force Cal test rig brackets can be fitted whilst the vessel is still in production.
  • When the vessel to be calibrated is released from production, all the pipe-work connections to the system should be checked for adequate flexibility.
  • Next, checks are made on the load cell mounting kits and clearances to ensure there is no mechanical interference to the load cells.
  • Now, having checked with the vessel is empty, the load cell millivolt output is checked and the reading recorded.
  • Next, assuming the vessel is empty, a zero calibration is carried out to the system weight Indicator.
  • Now the Procon Force Cal Test Rig is (can be) fitted , ensuring no load is applied to the vessel.
  • Once this is done, the Force Cal reference weight indicator is zeroed.
  • The Force Cal Test Rig is now used to load the system in 10 percent steps to (say) 80 or 90 percent of maximum load. The millivolt and weight reading results are recorded at every step.
  • At full load the calibration is adjusted if required.
  • Now the Force Cal test rig is let down and the zero point checked.
  • If any adjustments have been made, the calibration cycle must be repeated to confirm correct calibration adjustments.
  • Finally the test results are entered into the lap-top allowing the calibration certificate to be produced.
SECOND METHOD - LIFT UP

The on-site set up and use of the Force Cal “Lift Up” method is carried out as follows:

Firstly before entering the work area, the necessary work permits are obtained.

  • When the vessel is released from production, all the pipe-work connections to the system should be checked for adequate flexibility.
  • Next, checks are made on the load cell mounting kits and clearances to ensure there is no mechanical interference to the load cells.
  • Now, having checked that the vessel is at least 80 percent full of product, mount the Procon Force Cal test rig kit on the calibration plinths, making sure all the jacks are clear of the active weigh vessel
  • Now the Force Cal reference weight indicator is zeroed and t he system weight indicator reading is recorded.
  • The Force Cal test rig is now used to remove actual load in 10 percent steps to say 80 percent of maximum load. The millivolt and weight reading results are recorded at every step.
  • At full load, any error is recorded before letting down the Force Cal test rig jacks.
  • The system weight indicator calibration is now adjusted to match the gain of the Force Cal test rig and the new system weight indicator reading is recorded.
  • If any adjustments have been made, the calibration cycle must be repeated to confirm correct calibration adjustments.
  • Finally the test results are entered into the lap-top allowing the calibration certificate to be produced.
THIRD METHOD - DUAL OPTION

The on-site set up and use of the Force Cal “Dual Option” method is carried out as follows:

When the vessel is released from production, it is checked to see if it has been left empty or full of product

If the vessel is EMPTY the “Dual Option” test rig brackets are used to carry out the normal “Push Down” calibration procedure.

  • If the vessel is FULL, the brackets are used to carry out the normal “Lift Up” calibration procedure
  • Meanwhile, if the vessel is left half full you still have the capability of checking the system over the full working range.
  • In this situation, the “Lift Up” mode is used to re-verify to zero, whilst the “Push Down” mode is used to re-verify to full capacity.