Development Of IP Grade Test Equipment Based On The Differential Pressure Leak Test

With the great improvement of living standard and cell phone technology, theconcept of "Three Anti Cell Phone”(hereinafter referred to as TACP) has beengrowing popular. TACP is a kind of cell phone with a certain dustproof, shockproofand waterproof function, mainly aimed at young users loving outdoor sports orprofessional users with special needs. Meanwhile, the increasing civil cell phonesrequire the same protection functions of TACP.At present, the majority of cell phone manufacturers and relevant certifyingagencies define the waterproof function according to the national standard IP rating.The cell phone would be immersed into the water of1meter deep for30minutes, andthe inspector has to observe with naked eyes and judge whether the cell phone meetthe requirement of IPX7standard. However, this method does not apply to the fastpace of cell phone production line, and the dehumidification process after thewater-immersed test has been plaguing all the manufacturers.This paper firstly introduces the standard and implementation method of theTACP IP rating test，and clarifies the practical problems to be solved. Combinedwith the actual situation of engineering and based on the principle of differentialpressure leak detection, this paper introduces a detection system, which takescompressed air as medium, to detect the waterproof function of cell phones. Throughthe core components selection and PLC program design, the system precision,reliability and test efficiency have been greatly improved. The testing circle of eachcell phone is less than30s, and the dehumidification process is eliminated.When the traditional differential pressure detection method is applied, thecompressed air would be charged into the working piece, and the final judgmentwould be made according to the inner pressure decay. However, since the cell phonehas no suitable port for air charging, the differential pressure detection method has tobe modified.This is the essential content to be explored and is also a potential new detectionmethod for sealed products. Then the key technology of software and hardware design and debugging experience would be introduced and shared, and the developmentprospect of IP rating test equipment would be discussed.The equipment operation in Huawei Communication Equipment (Shenzhen) Co.,Ltd’s proves that the detection equipment which introduced in this paper is feasible,effective and reliable.