
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.

»DEFINE THE WORKSPACE REQUIREMENTSAccurately 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 LOADIt 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 RANGEDefine 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 EQUIPMENTDon'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 RATESThere 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? |


Copyright © 2010-2011 Envirotronics, Inc.