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Simple Shear Calibration Handbook

Owned by Dan Zanet
Last updated: Feb 09, 2021 by Diogo Teles (Deactivated)
7 min read

 

This handbook applies to EMDCSS and any other related Simple Shear machines

The EMDCSS Calibration Jig Handbook

© GDS Instruments Ltd

 

EMDCSS exclusive calibration jig

About

The manual explains how to set up the calibration jig, including the vertical, shear and horizontal load cell calibration setups.

 

Overview

 

What is it?


The EMDCSS Calibration jig is used to calibrate the vertical, horizontal and shear load cells in a GDS EMDCSS machine. The jig has three positions that are depicted within the drawings in this manual.

 

Items/Parts list:

A – Clamps to hold the jig in place using the EMDCSS frame columns.

B – Adjusting screw and nut. This allows docking of the shear anchor bracket and is also used to apply load to the shear load cell during calibration.

C – Calibration reference load cell.

D – Shear anchor bracket. Used to attach the jig to the shear loadcell or the lower platen in the EMDCSS.

E – Calibration load cell cable. Use this to connect to either a GDS serial pad or a GDS DCS box. A DIN-LEMO adapter will be supplied for connection to the DCS box as a LEMO connection will be required here.

F – Vertical anchor bracket. Used to calibrate the vertical axial load cell. 

 

 

 

All bolts that are required to attach the calibration jig to the EMDCSS are supplied from GDS.

Calibrating Load Cells         

Jig Installation - Vertical (Axial) Load Cell

 

 

 

 

In order to calibrate the vertical loadcell, make sure that all pedestals are removed from the machine leaving only the blank base.

 

 Assemble the calibration jig as shown in the pictures.

 

Make sure there is enough room to place the fully assembled calibration jig into the EMDCSS, you may have to retract or extend the vertical axis to allow this.

Ensure that the calibration jig is in a central position before moving onto the next step.

Bolt the vertical anchor bracket (part F) to the lower platen of the EMDCSS, using displacement control target within 2-3mm of the top of the calibration jig.

Ensure the EMDCSS is disabled now (press the stop button or turn off the machine).

Using the bolts provided (part D), bolt the calibration jig to the shear load cell. If required the adjusting screw (part B) can be used to adjust the height of the calibration jig in small increments safely.

 

 

 

Frontal View

 

 

 

Lateral View

 

When the calibration jig is firmly in place, the reference load cell can be connected to the serial pad or DCS box using item E and the calibration can begin using GDSLab.

Remove the calibration jig from the machine, the EMDCSS can then be re-enabled.

Jig Installation - Shear Load Cell

 

 

 

 

 

Set out the calibration jig as shown in the first picture (position 1) using parts A,B,C,D,& E. This is the same layout as shown in the (main) first page picture of this handbook.

Loosely attach the calibration jig to the vertical bars of the EMDCSS.

Bolt the load cell, using the screw to adjust the position.

Tighten the clamps onto the columns to secure the calibration jig in place.

Using part E and connecting to the serial pad or DCS box you can then begin the calibration process for the load cell.

 

Jig Installation - Horizontal Load Cell

 

 

 

 

 

To calibrate the horizontal load cell in the EMDCSS you will require items A,B,C & E.

 

Similar to the set up for the shear load cell, you can use the EMDCSS to get the correct distance for the calibration jig to fit correctly, then use the adjusting screw and nut (section B) to apply slight adjustments.

 

When the calibration jig is firmly in place the load cell can be connected to the serial pad or DCS box using cable E, and the calibration can begin (see section 2.4 below).

 

Applying load using the calibration wizard

For AdvDCS V2 based systems, please follow the instructions presented in 214 GDS Helpsheet - Change, update or create transducer calibrations in AdvDCS V2-based systems.
For any other system, please refer to 219 GDS Helpsheet - GDSLab calibration wizard .

Simple Shear Calibration

 

 

Shear Load Cell Calibration (waiting for Tom on this one for a better picture)

  • Remove the pedestal and the top cap

  • Attach the shear calibration support (long) (5) to the shear axis using the head bolts (8)

  • Place the spacer (7) on top of the (short) calibration support (6) and attach them both to the load cell using the head bolts (9)

  • Attach the load cell (3) to the (short) calibration support (6) and secure it with the head bolt (11)

  • Screw the load cell stud (2) into the other end of the load cell using the short side of the stud

  • Screw the adjuster block (10) to the stud (2). Only one of the female threads of the block fits the thread on the stud.

  • Extend the vertical actuator until the threaded socket on adjuster block (10) lines up with the bolt hole on the short side of the shear calibration support (5)

  • Place bolt (4) in the bolt hole on the short side of the shear calibration support (6) and secure it loosely with nut (1)

  • Move the shear actuator until you are able to screw bolt (4) into the adjuster block (10) - but DO NOT screw the bolt in yet.

  • The distance between the shear support plate (5) and block (10) must be only 1mm or 2mm longer than the width of nut (1). At this point no further movement of the actuators should be needed, both should be set to "Hold"

  • Screw bolt (4) into the block (10) adjusting nut (1) as required. Screw-in bolt (4) as far as possible. The bolt head should fit in the recess of calibration support(5)

  • Use nut (1) to lock bolt (4) against calibration support (5)

  • Using a spanner, turn adjuster block (10) clockwise or counterclockwise slowly to apply a positive or negative load on the load cell during calibration

 

Axial Calibration

  • Remove the pedestal and top cap

  • Attach Load cell (3) to the long end of calibration support (6) using bolt (11) making sure the bolt head is fully contained within the recess on the calibration support

  • Attach calibration support (5) together with the load cell (3) directly to the shear load cell on the vertical actuator using bolts (8)

  • Pass bolt (4) through the bolt hole on the long side of calibration support (6). The bolt should be sticking out parallel to the short side of the L-shaped calibration support (6) and the bolt head should be fully contained within the recess of the bolt hole

  • Secure bolt (4) to the calibration support (6) using nut (1)

  • Attach calibration support (6) along with bolt (4) and nut (1) to the shear actuator, using bolts (8)

  • Attach the short thread of stud (2) to the bottom of the load cell (2) which now should be hanging from calibration support (5)

  • Attach block (2) to the long thread of stud (2) and screw it in as far as it goes on the thread, without tightening (this will need to be unscrewed later)

  • Move the shear actuator so that the tip of bolt (4) lines up with the threaded socket on the block (10)

  • Lower the vertical actuator until adjuster block (10) is about 1 mm away from the head of bolt (4)

  • Unwind block (10) by hand until it starts screwing into bolt (4) on the other end. Screw-in bolt (10) by hand until you start feeling resistance