Dos and don’ts
Salt spray chambers are also called corrosion test chambers, this testing instrument is widely used by industries where metal plays a crucial role. Salt spray chamber is used to adjudge how the specimen would behave when subjected to the salt laden humid environment. Every metal behaves differently in the same condition. For instance, iron may tend to corrode easily in 2 ml of fog whereas gold may remain unaffected in the same fog. Having a testing instrument is not enough; what more important is, how to use it efficiently. Here is the list of dos and don’ts when using a salt spray chamber for checking corrosion resistance of metals.
1.Do maintain the temperature of lab below 45ºC. As salt spray chamber takes the ambient temperature from the surrounding and take it up to 45ºC. It is always advised to operate it under low temperature to get accurate results. However, temperature inside the chamber could go up to 49ºC
2.This device uses NaCl solution to create salt laden fog. Do maintain the pH level of the solution by keeping the container of the solution near the chamber. Imbalance in the pH level may not give accurate results. The auxiliary chamber can be installed on the 8ft height adjacent to the chamber.
3.Do keep on checking the level of fog for best results. It approximately creates 1-2ml of fog per hour. If it decreases, the working of instrument needs to be checked. However, if fog created is more than 2ml, it is not a cause of worry.
4.Do keep the test specimens at an angle of 20º. According to JIS, the sample must be placed at a specified angle in the test conditions, failing to fulfil the conditions would be considered as inaccurate test conditions.
5.Do keep the automizer in the center of the chamber. In some models, manufacturers make the automizer movable and can be kept anywhere inside the chamber, it is always advised to keep it in the center. It creates fog, if not placed in the center there will not be uniformity in fog distribution inside the chamber.
6.Do not open the chamber once the test has started. Opening the chamber may result in fog dissipation in the surrounding atmosphere. This means after closing the lid, the test will start from null. According to standards, the test can be ‘paused’ for some time to check the status of samples inside.
7.Do not keep the test chamber near the things which have a tendency to get corroded.
8.Do not open the chamber lid immediately. Presto corrosion test chamber has the feature of auto air purging, which allows the fog to settle down in the form of mist. Air purging can be done manually when the test is to be ‘paused’, on completion of test automatic air purging gets activated.
9.Do not keep the test sample near the wall. There should be some space between the wall of chamber and specimen to allow air flow. If the sample is within close proximity of wall, it would result in high heating and inaccurate results can be seen.
10.Do not run the test when the level of NaCl solution is low as it may lead to damage of the device.