This equipment is the Air Leak Tester on the EGR Housing Air Leak Tester.
It detects leakage on the housing of the part of a motor vehicle and uses a measuring instrument using the pressure differentiation detection method to set leakage amount to decide on OK/NG. 
The EGR Jacket detection and Water Jacket detection is done separately.
Detection level is ±5% of the test pressure and possible to display on ±1 pa.