AB-LT

The AB-LT an Allen Bradley PLC based family of leak testing systems which performs non-destructive testing to inspect the integrity of parts which have leak-tight requirements.

Each system is custom designed around the customers test requirements and often includes value-added functional testing and component inspection while performing the leak test.

This leak tester is often configured with multiple test channels, allowing simultaneous testing of multiple parts during each test cycle.   Each testers has the built-in capability to operate complex fixturing and perform other value-added testing/inspection during the leak testing operation.

Standard Features:

Allen Bradley SLC-503 Programmable Logic Controller Analyzer with custom programming complete with precision test logic and calibration capability.  Completely expandable design allows simple upgrades/expansion of capabilities as the users needs change.  Electronic control and precise repeatability provide quantifiable test results and eliminate operator decision making as seen with other test techniques such as immersion (dunk), soap solution and visual gauge based testing.  

16-Bit Analog to Digital Resolution offers ultra-fine resolution to detect even miniscule leakage quickly and with superb repeatability.

32+ Programmable Inputs/Outputs allows optimal flexibility in mating of the test analyzer to fixturing. Eliminates the costly requirement of adding an additional PLC to an Analyzer-Only when using multiple motion fixturing. System remains upgradeable for almost limitless control and testing possibilities.

Built-In Multi-Channel Transducer Capacity as each test system is constructed with the capability to optionally upgrade to 4 or more independently controlled testing channels with minimal increase in investment.

Allen Bradley PanelView Plus 600 User Interface simplifies parameter input and allows the following to be displayed digitally:

• Fill / Stabilize / Test / Exhaust Timers
• Current PSI
• Measured Pressure Change (∆-P)
• Measured Leak Rate (SCCM)
• Part Counters

User Programmable Windows for Test Pressure and Leakage Limits allows user to enter min/max values for critical parameters used to determine whether part has failed or passed.

Leakage Measurement in Standard Cubic Centimeters/Minute (SCCM) or Pressure Change (∆-P) enables user to display leakage in the format they prefers. SCCM is commonly used in automotive market segments. Appliance, medical and electronic markets commonly use ∆-P.

Compensation & Calibration Menus allows user to "teach" the tester what a known passed part will look like as well as how that part will look with a known (certified) leak rate orifice installed. Used most often when displaying leak rate in SCCM.

Multi-Level Passcode Protection limits parameter adjustment to qualified personnel only.

10 Test Program/Setup Memory allows storage for instant recall, minimizing tool change time.

Certified Leak Test Orifice allows user to perform both periodic calibration and verification that tester is programmed properly to detect target leakage.

Precision Sealed Industrial Electronic Pressure Transducer allows ultra-precise measurement of pressure changes typically to the nearest 0.0001 PSI.  Sealed construction prevents damage to transducer even when liquid is present in test air lines.

Manual Precision Test Pressure Regulator allows user to manually adjust pressure settings with fine-tuning control.

Zero-Leakage Fill Valve(s) with Failsafe Supply Ventilation used at each discreet test channel.  Unlike standard industrial valves, these precision valves are designed to prevent even miniscule leakage through the seals.  However, because of wear, no seal lasts forever.  Failsafe ventilation protects each test cycle against a false “PASS” resulting from leakage through the fill valve due to gradual seal wear or contaminant in the valve.  During the Stabilize and Test steps (when the fill valve traps test pressure within the part), a secondary ventilation valve releases pressure from the supply side of the precision fill valve.  By releasing this pressure, any possible leakage through fill valve will result in test pressure being vented backward through the fill valve to atmosphere, causing a pressure drop during these steps which virtually always cause the test to fail (instead of re-supplying the test part with pressure were the supply side not to be vented to atmosphere).     

NEMA 12 Enclosure offers complete protection of critical electronic and pneumatic system components in even the worst industrial environments.

Standard "Off-The-Shelf" Hardware minimizes downtime delays and expense as common Allen Bradley hardware and standard pneumatic components are the foundation for the system and are carried by most local distributors.  Virtually eliminates the need to return the analyzer back to the factory for repair of proprietary circuitry.

Zero Force Cycle Activation Switches reduce operator fatigue.

Large Yellow or Blue IN PROCESS Indicator Light allows operator to easily notice that the test cycle has begun.

Large Green PASS Indicator Light allows easy viewing of successfully tested part status by the operator.

Large Red FAIL Indicator Light allows highly noticeable indication of tested part failure by the operator.

Two English Language Manuals provides detailed documentation and instruction of installation, operation calibration, maintenance and troubleshooting.

Warranty:  Free from materials and workmanship defects for one year from delivery.

Sequence of Operation:

1. Operator loads part(s) to be tested into leak test fixture(s).

2. Operator initiates both cycle activation switches.

3. Leak test fixture(s) seal heads actuate to seal part. 

4. Operator is permitted to release cycle activation switches after all motions have been completed.

5. Leak test analyzer pressurizes part(s) with compressed air.

6. Leak test analyzer traps pressure within part(s) and vents pressure supply line to atmosphere.

7. Leak test analyzer measures decay of pressure within part(s) and results are compared to user programmed limits.

8. If test passes, a green indicator lights and the leak test fixture(s) seal heads retract from part(s), venting pressure to atmosphere.

9. If equipped, optional part marker(s) actuate, imprinting character code on passed part(s)

10. If test fails, a red indicator lights and the leak test fixture(s) seal heads remain closed, awaiting operator acknowledgement of the failure by depressing the cycle stop button.

11. If equipped, no optional part marker(s) actuate.

12. Operator removes tested part(s) from leak test fixture(s).