1, Preface
Although Environmental testing industry is a traditional industry that started not too late in China, getting truly universal is around the latest 20 years. Nowadays, there are more than 300 factories and companies in various scale in China, but very few enterprise is certainly understand and grasp the core and essence of products. For customers, products are just like seller’s market, they have many choices, but because few high-skilled users know the usage function of product, and in addition, the so-called pre-pay policy in transportation and sales operation in industry, and the distributors play game technical index, and so on customer’s tragic of history. But today we are not to talk about that bad history, I’m in technical work, and i’m teaching you guys to avoid being confused and conceived.
So i made some explanations on frequently-used temperature and humidity index and common configuration, hope it will help users. Of course, there are many environmental test indication project, and configuration operation patterns are all has its advantages.
2 performance index explanation
1 temperature index
1)temperature range: temperature range refers to the ultimate temperature that lab oven can suffer or reach. Usually, constant conception that can be control should be a long-time stable operational extremum relatively. Generally, temperature range contains extreme high-temperature and extreme low-temperature.
The temperature range of Clean high temperature test chamber is relatively simple, usually low temperature add about 10~50℃ based on normal temperature, and high temperatures are at 200、300、400℃ called nominal temperature.
The ultimate temperature of high and low temperature chamber is around +180℃ according to Euro-American product’s nominal temp; Japanese product’s nominal temperature is +150℃, and the Milky way sida’s nominal temp is +100℃, technical protocol, in fact, can sign to about +130℃. Of course, on the basis of user’s requirement, most of companies’ technical agreement can be sign to +180℃, but whether can conduct extreme temperature test, users must carry through physical verification. Personally, if no need, high temperature at 130℃ is suitable.
Extreme low temperature is mainly decided by cooling capability and cooling mode, here, i just introduce the configuration index of mechanical compressional mode cooling system. Normally, monopole cooling capability is -45℃,and normal index is -40℃; despite overlay extreme cooling capability can reach -82℃ theoretically, but in consideration of cooling capability is too small below -70℃, so the index is usually -70℃. Because some users don’t use lower temperature ovens, most of companies will push out -20℃ even 0℃ index that have high cost performance.
2）Temperature fluctuation
This index is also called temp stability, that is when the temperature is stable, the temperature difference between the highest and lowest in any given time interval and space interval. There’s a little difference between ‘work space’ and ‘work room’, work space take rid of the lab oven wall. This is a control technology of checking products.Usually, standard requirement index is ≤1℃ or ±0.5℃.
Some companies have a nominal at ±0.2℃ to advertise control technology, in fact, The control temperature fluctuation that can’t reach to the temp uniformity and temp difference below ±0.3℃ in temperature testing is hard to be eligible. Also, the controling temperature fluctuation that cannot reach to ±0.1℃ of humidity is hard to be stable. Attention, lab oven like aging test chamber etc. also have temperature stability index, but that’s not the same concept.
