Harry McLean’s book “HALT, HASS, and HASA Explained: Accelerated Reliability Techniques” will be released in the next few weeks. You can pre-order at:
HALT, HASS, and HASA Explained: Accelerated Reliability Techniques
This is planned to be a 6 x 9 hard cover, priced at $39/members of ASQ and $65/list.
In this author’s opinion, it is one of the best books written on the subject and I highly recommend it.
Are there any HALT chambers that utilize swept-sine excitation with the ability to switch to random vibration? It would be interesting while thermal cycling to apply random vibration then switch to a frequency-swept (or stepped) sine vibration. The reason I ask is I wonder whether HALT is a good indicator of weakness when there might be resonance in the set-up or product.
There are only about 7 manufacturers of HALT chambers based on the definition that a HALT chamber must have pneumatic vibration and rapid cycling using LN2. To my knowledge, none of the chambers have this capability. However, if you expand HALT chamber beyond this and include any chamber that can be used to test products to failure and expose product weaknesses, then there are chambers that use swept sine/random (most ED shakers can do this).
Having said this, if you know how to read a PSD plot that comes off of a traditional HALT chamber, you should be able to pick up the resonances of the product by doing a comparison plot of table vs. product.
Hi Admin,
May I know which are the 7 manufacturers of HALT chambers as mentioned in the second comment ?
Vincent
Andrew,
You are talking about an AGREE chamber, I know Thermotron makes them. The AGREE chamber is basically an ED shaker mounted through the floor of an environmental chamber. I belive you can get them equiped with LN2 cooling and you will have the rapid temperature feature of HALT plus the swept sine and random vibration capability of an ED shaker.
I look at amazon and there is quite good evaluation of first edition:
http://www.amazon.com/Halt-Hass-Hasa-Explained-Accelerated/dp/0873894898.
Hi all,
Does anyone know the difference between the original (2000) and revised edition (2009) of Harry McLean’s book “HALT, HASS, and HASA Explained: Accelerated Reliability Techniques” ?
By the way, which are the companies that really practised HALT Test on their products ?
Vincent
Hello, Vincent. This is Harry McLean. Extensive clarification changes were made as well as to add more examples and sections in a couple of chapters. One example that comes to mind is the Must Meet Limits which are now called Guard Band Limits regarding. A table with the three different vibration technologies and their Guard Band Limits is now included. Another addition is a section on the minimum requirements of a failure analysis lab. The result of the extensive review and critique is a clearer and more concise book.
Regarding the question on who is doing HALT varies as some use test labs like Mike’s while others buy their own chamber. Many from both camps do not wish to have their names or details divulged so, I would like to refer you to Tom Peters at QualMark (888-425-8669) and of course, Mike Silverman (408-472-3889) and they can share with you their customers who are willing to share information. As far as I am concerned, Hewlett-Packard (DeskJet Printers), Xantrex (Power Supplies both, commerical and high reliability types as well, as PV and wind inverters), Honeywell Avionics, Medtronics (Redmond, WA), and Microsoft.
I trust all that I have shared clarifies and answers your questions. Fell free to contact me on this blog Have a great day!
Hi Harry,
What are the three different Vibration technologies discussed in your new book ?
May I have your email address, so that I can contact you directly ?
Vincent