How to maximize your chamber purchasing dollars
The purchase of an environmental test chamber may be a relatively large capital expenditure for your company. As a manufacturer of environmental test chambers, we would like to assist you in making the best purchase possible.

Obviously, your selection of a reputable vendor is very important, however, your responsibility begins with preparing a well written purchase specification. this will ensure that the equipment proposed by your vendors will absolutely meet your minimum requirements.

Envirotronics would like to provide you with a few helpful hints that may aid you in your specification writing process. The items discussed here are generally the most expensive aspects of a test chamber. Our goal is to highlight and expose those areas that can provide you with the most cost savings.

As a minimum, the following information will be required by your vendor in order to properly respond to your needs:

»DEFINE THE WORKSPACE REQUIREMENTS

Accurately specify the product(s) to be tested to insure that the proper chamber volume is provided. Provide detail on the product composition, so that adequate space will be available for air circulation around the product.

»DEFINE THE PRODUCT LOAD

It is to your advantage to be as specific as possible in providing product information. If possible provide a product composition, including specific heights and weights of the various materials within your product. Also include any fixturing present in the chamber.

Arbitrarily increasing your product load could mean that the next larger horsepower system is needed to meet your performance requirements, thereby costing you more money. If the product will be powered up during any of the tests, also note the power that will be dissipated within the chamber and at what portion of the cycle. Most customers do not apply power in the cooling transition, again to reduce the refrigeration system size.

»DEFINE THE OPERATING RANGE

Define the desired chamber operating range as well as the range in which the product will be tested. If purchasing a humidity chamber, you should also be aware of the humidity requirements. Remember, humidity ranges of 20% to 98% are generally easily achievable. Ranges below 20% will usually require expensive air drying systems and solid state sensors.

Also remember that for test requirements above -30 degrees C, a single stage refrigeration system can be provided. The utilization of a single stage system versus a cascade system will provide substantial cost savings.

»DEFINE OPTIONAL EQUIPMENT

Don't specify an overabundance of "bells" and "whistles" with your system. Most vendors will provide a list of the most common options available on the model being quoted.

If you have specific requirements, please make these known. There are certain options that may require a vendor to quote a specific model or series chamber. For example, if your system is to be used in conjunction with a vibration system, an "AGREE" type chamber with a removable floor would be quoted.

»DEFINE TEMPERATURE TRANSITION RATES

There are two key elements in properly defining transition requirements. One, are your needs to monitor chamber air temperature (the normal method), or must rates of change specified be seen on the product?

»CHAMBER DO'S

  • Ask for a quote on a vendor's nearest standard model that will meet your requirements, then ask for options that are available, and their individual prices.
  • Consider buying fewer optional items, such as ports, windows, etc., however, purchase the largest size available

»CHAMBER DON'TS

  • Don't just specify a model number of a chamber that you currently own. even though the chamber volume may be appropriate, the refrigeration system may not be sized for your new application. Technological improvements may mean that the same job can be done today with less refrigeration. Remember, a system with a larger refrigeration package will:
    •

    -have a higher capital outlay

    -have higher operating costs

    -have higher installation costs

    -have increased maintenance costs

    • Don't be afraid to ask your vendor for a printout of their load calculations so that you can compare system performances. have your salesman explain why a specific horsepower system was proposed.
    • Don't forget to consult with your facilities personnel regarding move-in restrictions, and water and power availability.
    • Don't be afraid to ask that seemingly "dumb" question. When spending your company's money, you are entitled to know everything about your purchase.

    »REMEMBER, properly specifying your test chamber needs will ensure that:

    • As a minimum, the equipment purchased will in fact meet your specified requirements.
    • You have purchased the equipment necessary to perform a function at the lowest possible cost without sacrificing performance or quality

    Other points to consider when evaluating potential vendors:

    • Review the proposed warranty. Remember that the confidence a company has in its products is expressed through its warranty.
    • Ask for a list of satisfied customers. Even though a reference list can be assumed to contain only happy customers, the confidence that they provide can not be equaled.
    • Verify that equipment manuals are complete with system drawings and commercial parts lists and not exclusive internal part numbers.
    • As with any business, experience can not be beat. If there is any doubt about purchasing from someone, visit their plant, meet their people, and verify for yourself that you would be willing to purchase their equipment.

    If you have further questions about purchasing an environmental test chamber, please feel free to contact our sales department at:

    Phone (616) 554-5020
    Fax (616) 554-5021
    ›sales@envirotronics.com