TM Electronics Front Panel for the MDT-500

Overview
The integrity of flexible / medical-type packages can be demonstrated with a nondestructive package test method. The method finds leaks in packages manufactured from nonporous films, foils, or laminate materials. The pressure-decay test method uses a custom test chamber and the MDT-500C leak tester. Using this method, holes as small as 10 µm can be detected from pinholes, punctures, or seal channel leaks. The MDT-500C leak tester provides simple-to-use, menu-driven controls for easy setup and key-lock security to prevent operational changes. A graphic plot of pressure versus time is shown on the LCD along with other data including SQC/SPC control charts, histogram, and statistics for mean, standard deviation, and range.

Leak Testing
The speed of the MDT-500 begins with its high resolution. The MDT-500 uses a proprietary pressure sensing system that increases both its sensitivity and its stability. The single ended system reaches 17 bits of resolution, making its pressure resolution equal to many differential testers. Decay resolutions of less than 0.02 in H2O (0.0007 PSI) are easily achieved. The precision of the MDT-500 begins with the stability of its test pressure. Since a stable test pressure is vital to the repeatability of a leak test, the MDT-500 is equipped with the best pressure regulator available. This not only increases its stability, but also simplifies the test process since the test pressure needs to be set only once.

Flow Testing
To simplify occlusion tests and 'gross' leak tests, a precision flow sensor is included in the MDT-500. A simple occlusion test can take less than one second to complete, saving time and making the test much more cost effective. Also, using the flow sensor to detect a "gross" leak can decrease the amount of time needed for that test. Still, pressure decay remains the best test method for finding small leaks since it is much more precise and repeatable.

Simplicity
A bright 3 in. x 4 in. LCD display and an easy to follow keypad are two key elements to the simplicity of the MDT-500. The familiar "ATM" (Automatic Teller machine) style format can easily take a new operator through a single test setup, or guide an experienced operator deeply into the more powerful features. This design gives the user and easy to follow path. It needs little if any training to setup a test procedure, to save a setup program in memory, or to use any of its many statistical functions. Each screen moves easily and simply to the next screen. Menus define the role of every key during the test and setup. When a test is complete, a bright green light verifies a good part, or a bright red flashing light indicates a reject.

Built In Statistics
The built in statistics mode simplifies process control, and is a standard feature of the MDT-500. It automatically records and processes the results of up to 500 tests stored in the data log, a painstaking task that must still be done by hand when working with many other leak testers. The MDT-500 needs only the touch of a key to display the Standard Deviation, Minimum, Maximum, and Mean data points. A histogram, 'X-bar' and 'R' Charts track statistical trends and can also be seen with the touch of a key. The simplicity of built in statistics means there is no need to buy additional computer equipment or struggle with a difficult interface.

Outputs
The MDT-500 is a microprocessor based instrument, so it is essentially a computer. As a computer, it can access printers and other computers with the same ease as your desktop PC. To take advantage of the printing capabilities that are a standard feature on the MDT-500, an 80 column Epson compatible printer is needed. The microprocessor will automatically sense when it is connected to a printer and print the numerical results of every test. Upon request, the MDT-500 will also print the DATA LOG, a graphic plot of the pressure decay and all of the statistical results. Using your existing SPC program or database can increase the value of the test results, so saving the data has been made as easy as connecting the MDT-500 to a computer.

Security
A key lock has been included to increase the security of the MDT-500. Easy to understand graphics show the locked and unlocked positions. In the locked positioning, no changes can be made to any of the setup parameters. Also, once in a test, the only functioning key on the front panel is the Stop/Start key, regardless of whether the system is locked or unlocked. The lock feature is available to prevent accidental changes in a setup program. In addition, single product lines will find it valuable to secure their test parameters permanently.

Displays
The operator can choose from eight different display styles to view the test results. They include a large numeric display. In both the test results and set up modes, the MDT-500 uses one inch tall digits in its numeric display. Large enough to be seen from a distance, the display makes viewing the test results even easier up close. Also, for the first time in a leak test instrument, a graphic plot of the pressure decay can be displayed. The plot shows details of the test that could otherwise be missed. In addition, a data log of the previous test results and statistical analysis generated from the data log come into view at the touch of a key. Histograms, X-bar, and R-charts are also available. These features, usually reserved for more expensive systems, are available in real time with no need for a computer interface.