Is it possible to test medical tubing for both small leaks and unimpeded flow at a rate of 3.75 seconds per part while also meeting ISO 13485 requirements?
A family of plastic medical tube sets require both leak and flow testing at 62kPa (9 psig) to determine that they function as designed—without significant leaks (detecting leaks as small as 0.1 sccm) and with unimpeded flow rates (user selected 0.4 – 20.0 sccm). Four different tube configurations are to be tested.
While quality cannot in any way be compromised, competitive pressures for these relatively low-cost medical products is such that a relatively fast production rate of 16 fully tested parts per minute (3.75 seconds/part) must be achieved.
The InterTech Solution:
EtherNet/IP enabled InterTech Med75 dual function leak and flow test instruments fully test 16 parts per minute with GR&R of less than 20% in accordance with ISO 13485 Requirements for Maintaining Consistent Quality Systems.
Test instrument software must be flexible enough to meet application specifications. Software used at a higher level must seamlessly integrate with assembly systems and all other software used in monitoring plant operation
There is no one-size-fits-all software for test-centric assembly. Anyone who tries to tell you differently is trying to rationalize a proprietary software design that won’t matter much and will likely cost you more—upfront or in lower yields
A short list of systems to consider includes:
NI LabVIEW, Diadem, and RTOS FPGA HMI control systems
Ethernet/IP, OPC, Modbus, Profibus, TCP/IP and BSD Sockets protocols.
SQL-compliant database systems
Bottom line: There are many software options that are best-match for your test and assembly application……Contact IDC for in-depth understanding on this whole topic including extensive white papers and knowledge.
We in the USA always talk about how everyone speaks English. This may be true of top managers around the world, but in general, plant engineers are most comfortable with their own language.
When you speak to others in their own language, you gain respect, but at the first difficulty, people tend to revert to their native tongue. Some words, however, defy translation. In China, for instance, the term “fuel injector” has no precise equivalent, and loose translation can lead to confusion between people of different nationalities.
Sometimes in leak testing, it seems like a translator would be helpful even when we all speak the same language! For instance, no matter where I go, it seems there is much confusion about mass flow and pressure decay.
With all the language considerations in today’s global marketplace, the best thing we can do to help our customers is to equip controls with different language options. Interactive controls like touch screens help even more.
I predict technology will trend toward devices that utilize the native language of operators and engineers through traditional and other sensory inputs such as touch screens. This is a top consideration at InterTech. How will your business overcome language barriers?
IDC Technology Updates – IDC is now offering an ultrasonic welding fixture which also doubles as a leak test fixture.
The sequence of operation is as follows: operator / robot loads parts, parts are welded, leak test completed, parts unloaded; the technology means the end user does not have to employ separate work stations which typically results in redundant load / unload times for the different operations required in welding and leak detection.
Contact IDC for further information on this innovative technology offering.
Now, one leak tester from InterTech does the job of many specialized instruments and is ideal for quality control in the lab: the new M1075-121y Universal Audit Tester.
The difference between this test instrument and others in the industry is a design breakthrough that eliminates the need for part volume matching as required in pressure decay methods.
“This is a transformative development in leak testing applications that require quick changeover and flexibility,” said InterTech President, Mr. Jacques Hoffmann. “It changes fundamental issues. We eliminate the need for specialized leak testing instruments in the lab. Now, the same instrument can be used for a large engine casting or a small solenoid – just change the part and go.”
Until development of the M1075-121y Universal Audit Tester, “small” parts required instruments with a “small” built-in reservoir, and “large” parts had to be tested on different instruments with correspondingly bigger reservoirs.
Specialized instruments are still best where application speed is paramount, according to Mr. Hoffmann, but he points out that as the instrument’s name suggests (Universal Audit Tester), this new & superior instrument is for labs and quality engineers.
“Whether it is incoming inspection, product development or supplier development, this is how to control costs and stay flexible, and more elegant compared to custom instrumentation dictated by part size or material properties,” said Mr. Hoffmann. “Now, with one leak test instrument from InterTech, quality engineers have more flexibility than they’ve ever had.”
Leak gaging with the M1075-121y covers a much wider range than other models. It handles an amazing array of volumes from 5 to 800 sccm. A bar code scanner interface, simplified calibration and touch screen menus make operation easy and intuitive.
idc universal audit tester eliminates the need for multiple reservoirs
USB Ports to upload/download data files and program restore/backup
RS-232 Com1 Port – data and control
RS-232 Com2 Port – serial port available for additional capabilities or RS485 option
EthernetPortto connect with factory/host network (TCP/IP)
Embedded web page server for remote viewing of instrument data and files
Password protection is standard and users can select language settings from English, German, French, Spanish, Korean and Chinese. All functions are menu driven and up to 99 different test programs may be selected.
The leak detector may operate as a standalone instrument or interface with a PLC or PC by various methods including Ethernet control (IP/TCP).
To know more about the Universal Audit Tester, get in touch with us today. InterTech has its Indian sales and demonstration offices in Chennai, Tamilnadu.
Single Station Bench-Top Leak Test System for Testing Oil Filter Adapters
idc single station bench top leak test system for oil filter adapter
Mass flow leak testing (using M1075y) provides a quick and direct measurement.
Five different filter variations can be tested as the clamp is designed to support interchangeable clamp springs designed for a specific filter adapter.Gage R&R meets automotive requirements of less than 20%.
Test specifications required;
Test Pressure: 6 bar
Accept/Reject Limit: 5.0 sccm
Test Time: 25 seconds approximate
Model Changeover: 5 different filter variations can be tested
InterTech has its sales and demonstration offices in Chennai, India. For sales enquiries, you may contact us at;
Read about InterTech Development Company’s low cost leak detection solution on the Auto Car Professional Magazine website.
InterTech Development Company, USA, has launched its new Eco-series 1 low-cost leak detectors in India. Designed around the company’s patented Pressure Decay process of leak measurement which offers both speed and accuracy in leak testing, the InterTech Eco-series 1 Leak Detector is a high-resolution (24-bit), pressure-change measuring instrument. It offers a touchscreen control panel for easy control and operation, an important feature that enables comprehensive use of the instrument’s impressive range of capabilities.
Packaged in a compact cabinet, the Eco-series 1 Leak Detector is portable and easy to use in on-site applications. It is also ideal for standalone Go/No-Go QC on test-benches of small and medium industries. At the same time, advanced communication facilities such as an Ethernet connection and User I/O port have been provided to allow integration of the unit into complex instrumentation panels. InterTech says the Eco-series 1 will find use in any size of industry — small, medium or large — also allowing for upgrade from standalone to being part of a larger panel..
For more details on InterTech’s leak-testing solutions, contact Ajay Athreya (099403-20718, firstname.lastname@example.org) or Ram Dharmarajan (098409-14544, email@example.com).
In parts one, two, and three of this “Leak Testing 101” series, we discussed three methods of dry-air leak testing—pressure decay, differential pressure decay, and mass-flow leak testing—including the pitfalls and hidden costs inherent in two-step pressure testing methods and the higher accuracy of single point measurement mass-flow leak testing techniques.
Is mass-flow leak testing always the best leak testing method? Absolutely not. When accuracy and cycle time requirements are not that stringent, pressure decay testing or differential pressure decay testing can be a better application match because test instrumentation does not require as much specialization and related cost. At the other extreme, when very small leaks of less than 0.01 standard cubic centimeters per minute (sccm) must be detected, helium mass spectrometer leak testing methods may be required. It is the only reliable method when an application requires detecting leaks as small as 10–4 standard cubic centimeters per second (sccs) or less.
There are several different helium leak detection methods:
Sniffer—The test item is pressurized with helium and an operator moves a sniffer probe connected to the mass spectrometer to localize the leak. This method is slow, nonquantitative but has the advantage of localizing the leak.
Accumulation—The test item is placed in a chamber and charged with helium. Helium leaking from the part accumulates in the chamber and after a certain amount of time, a sniffer probe checks for the presence of helium, i.e., a leak. While apparently inexpensive, this method has a number of shortcomings: presence of tracer gas from prior tests, lack of adequate circulation in the chamber, and long test times due to background effects. As a result, it will be difficult to provide quantitative testing with this method.
Vacuum leak testing with helium—Figure 1 shows how helium mass spectrometer leak testing proceeds. The part is pressurized with helium and the chamber is evacuated down to less than 0.1 mbar absolute to eliminate background effects. The presence of helium leaking into the chamber is then detected by the mass spectrometer.
Figure 1: Test item is pressurized with helium within a test chamber. The chmber is evacuated, drawing helium out of the leaking test item. Mass spectromter then samples the vacuum chamber.
Equipment costs, maintenance costs, extra time required to evacuate helium from test fixturing in between test cycles, and ever rising helium costs makes this method the method of last resort. Typical applications include: heating, ventilating, and air conditioning (HVAC) components; pace makers; aluminum wheels; and airbag components.
For these type applications where leaks of 10–4 sccs or less must be detected for product integrity or safety, helium has its well-deserved place in the repertoire of best-match leak test techniques to consider.
In the next part of this Leak Testing 101 series we will discuss miscellaneous other testing techniques including: hydrogen ultrasonic, bubble testing, and air under water.
If you would like specific questions on best practices for leak testing (and other testing topics) answered in future articles, please send me your questions at firstname.lastname@example.org.
Note: The above article has been reproduced from an article written by the author for Quality Digest
Not too long ago, when you wanted a product to be leak-proof, you simply put it under water, made sure it didn’t bubble, and thereby concluded there were no leaks. Such “bubble testing” takes time and depends on the operator’s ability, making it totally inappropriate for the modern production environment. Also, it doesn’t generate the quantitative measurements that are the lifeblood of quality assurance engineering.
Dry-air leak testing methods—some of which can detect leaks as small as 0.01 standard cubic centimeters per minute (sccm)—are the methods most commonly used today by a wide range of industries—from medical devices, to automotive, to appliances, and aerospace, among others. These dry air methods enable quality managers to define leaks quantitatively.
“No leaks allowed” standards are concepts of the past.There are a variety of dry air leak test methods and best-practice techniques for each type of method, which will enable compliance to ISO 9001 and comparable quality management standards to be achieved. Generally speaking, these dry air leak test methods include;
In addition, tracer gas testing and especially helium mass spectrometer leak testing, are used in more demanding applications where leaks as small as 10-5 standard cubic centimeters per second (sccs) must be detected in a production environment. If one truly understands leak testing application requirements and best practice techniques for these various leak test methods, the selection of which type of testing to perform is a rather straightforward matter.
The first step in designing a leak testing solution is to correctly define what the leak limits are. Leak testing applications laboratories begin with an engineering analyses of a specific application to determine and quantify how much a product or component can leak. Often, correlation studies are performed to verify if it is possible to use dry-air test methods instead of hydraulic fluids. Sample parts are tested as part of an initial engineering analysis. These determine the production requirements and leak standards to be achieved so that quality engineering of test solutions can begin. The first step in this process is to select the leak testing method that is the best match to application requirements.
In this “Leak Testing 101” series we will discuss the various dry air leak testing methods and the issues and techniques that affect testing costs and gauge repeatability and reproducibility (GR&R).
First, let’s take a look at the pros and cons of pressure-decay testing.
The big plus of pressure-decay testing—or at least the thought behind it—is that the leak detectors for pressure-decay leak testing have the lowest upfront cost. It is probably for this reason that the method is still in use, although in many applications the real costs of pressure-decay testing are actually much higher than many realize.
In the pressure-decay method for leak testing (see figure 1), a part is pressurized, the test circuit is isolated, and the pressure drop associated with a leak is measured. A transducer reads the pressure change. Calculations then convert these time/pressure readings into a measure of leakage rate. The higher costs of pressure-decay testing stem from the difficulties inherent in the test methodology. Pressure-decay leak testing is relatively difficult because measurements are highly vulnerable to changes in testing conditions such as drafts or temperature and there are often difficulties in determining the volume of test parts and test circuits, which must be known in order to calculate results.
Pressure Decay Method
Also, pressure-decay leak testing requires two measurements of pressure with sufficient elapsed time between measurements. When speed of testing is an issue, this built-in delay makes the pressure-decay method less desirable. More important, the two measurements and the time lapse significantly increase the potential for measurement error. The amount of time you need to wait between measurements varies. Sometimes, long intervals between measurements can make for extreme accuracy, but these long wait times are typically not practical. The larger the part volume, the longer it takes to measure the pressure drop. Moreover, very large flows are also impractical with pressure decay, because when pressure drops very fast, it will probably not be measured accurately.
Thus, although pressure-decay leak testing instruments have a relatively low upfront cost, the extra time it takes to perform testing (if the results are reliable enough for the given application) is another expense that needs to be factored in to overall cost. It can still be the best leak test method for a specific application, but the trend lines are in the other direction. Most applications now require tighter GR&R even for very low leak rates, often with large volume parts, and with a desire to keep test cycle times to the bare minimum to cut overall testing costs.When you factor all these considerations in, it often leads one to use other leak test methods instead.
In the upcoming issues of this “Leak Testing 101” series I will discuss differential pressure-decay testing, mass-flow leak testing, temperature compensation issues, and many other topics. By the conclusion of Leak Testing 101, my goal is to bring all quality managers up to speed on the real factors that affect leak testing cycle times, costs, and reproducibility.
If you would like your specific questions on best practices for leak testing (and other testing topics) to be discussed in future articles, please leave your comments and suggestions in the Comments area below.
ABOUT THE AUTHOR
Jacques Hoffmann is founder and president of InterTech Development Co., a world leader in test-centric assembly specializing in automated leak and functional testing with mass flow, hydraulic, helium, or pressure decay technology (ISO-17025 accredited). InterTech Development Co.-engineered solutions are used by hundreds of quality management, product design teams, and manufacturers worldwide and the company’s worldwide support organization maintains offices in North America, Asia, and Europe.
Note: The above article has been reproduced from an article written by the author for Quality Digest