Detecting leaks in a heat exchanger in operation

A device for detecting and assessing the size of leaks in a heat exchanger during operation thereof, said heat exchanger having a circuit for a higher pressure gas and a circuit for a lower pressure gas in mutual heat transfer contact, comprising:

• (a) means for temporary storage of a first predetermined amount of said tracer gas;
• (b) means for rapidly forcing said first predetermined amount into the lower pressure gas of said heat exchanger at an inlet of the lower pressure gas circuit;
• (c) means for sampling the lower pressure gas at an outlet of said lower pressure gas circuit following admission of said tracer gas into said lower pressure gas circuit;
• (d) means for temporarily storing a second predetermined amount of tracer gas, said second predetermined amount being higher than said first predetermined amount;
• (e) means for rapidly forcing said second predetermined amount into said inlet of said higher pressure gas circuit;
• (f) means for sampling the higher pressure gas at an outlet of said higher pressure gas circuit following admission of said tracer gas into said higher pressure gas circuit;
• (g) means for extracting tracer gas which is possibly present from the sample;
• and
• (h) means for measuring the quantity of extracted tracer gas.