Introduction to the calibration method of high and low temperature test chamber
The high and low temperature test chamber is to test the performance indexes of the parts and materials of related products such as electronic and electrician, automobile motorcycle, aerospace, ship weapons, colleges and universities, research institutes, etc. under the condition of alternating high and low temperature cycles. . The calibration has the following methods. In actual work, it is necessary to select a suitable method according to the actual situation. Below, our company will introduce the advantages and disadvantages of these calibration methods.
Captive Screws are fasteners designed to remain attached to guards or equipment. A conventional screw typically passes through a clearance hole in one part and then screws into a threaded hole in a second part - so the first part is clamped to the second. However, when the fastener is unscrewed from the threaded hole in the second component, it can easily separate from the first one.
A captive screw is designed to prevent this from occurring. It can freely rotate within the first component, with some axial movement, but it`s unable to separate from it. Captive screws are used when fasteners must remain attached to equipment, such as in cover panels. They are a requirement for several machinery safety standards.
Captive screws have a normal thread and a reduced diameter for the rest of the screw length. A captive screw is usually used with a retaining washer or a retaining flange. These have a hole with a short-threaded length. The threaded portion of the captive screw is screwed through this hole until the reduced diameter can pass freely through it. The washer or flange is then captive on the screw.
To install a captive screw on a panel using a retaining washer, the screw is first passed through a hole in the panel. The washer is then screwed onto the captive screw, until the reduced diameter section is reached, retaining the screw on the panel. To install a captive screw using a retaining flange, the flange is first pressed onto the panel. The captive screw is then screwed into the flange until the reduced diameter section is reached and the screw is retained.
Other forms of captive screw are also available that have pre-fitted caps in place of a retaining washer or flange. These caps can be pressed, bonded, or screwed into the panel or equipment to which the screw is to be retained.
Captive screw, Captive panel screw, spring captive screw FinExpress Precision Manufacturing(Dongguan) Co., Ltd , https://www.finexpresshardware.com
1. Calibration under no load conditions: the entire working area of ​​the high and low temperature test chamber is calibrated, the test sample becomes more re-calibrated, and the applicability of the high and low temperature alternating test chamber temperature can be effectively Evaluation. Its main disadvantage is that it cannot evaluate the impact of the test sample on the test chamber.
2. The high and low temperature test chamber is calibrated under load conditions: it can accurately evaluate the influence of the test sample on the performance of the test chamber, and obtain detailed information on the environmental test of key parts or parts of the test sample. The main disadvantage is that it requires recalibration when changing test samples.
3. Real-time measurement during use: not only the advantages of the method described in 1 and 2, but also the comprehensive environmental parameters of the test sample during the environmental test process, often used in the test of products with high environmental requirements . Its main disadvantage is that each environmental test requires the use of measuring equipment, usually in the test chamber calibration using the calibration method under no load conditions.