A compressor manufacturer wanted to install a pressure monitor on their large vessels for daily monitoring of pressure and periodic leak testing. They had been using a chart recorder for this purpose and wanted to optimize the process to eliminate costly maintenance and labor associated with using the chart recorder. The pressure port is located on top of the vessel and the chart recorder is sometimes only accessible using a ladder.
The solution was WIKA’s CPG1500 precision digital pressure gauge with data logger and WIKA-Wireless communication, which they used to perform both the daily monitoring and the leak test. The manufacturer now supplies their CPG1500s to their customers on tanks that require this feature. WIKA-Wireless allows the user to monitor and collect data during the leak test using the ‘myWIKA device’ app or a computer. This is a big advantage because there is no longer a need to maintain a chart recorder and it is not necessary to gain physical access to the equipment. In addition to pressure, a temperature reading can be acquired from the CPG1500.
Below is a sample that shows data taken during a leak test:
Timestamp |
Pressure / psi |
Temperature / °F |
Pressure Min |
Pressure Max |
8:55:03 PM | 797.87628 | 80.204 | 797.87628 | 797.87628 |
8:55:08 PM | 802.29645 | 80.204 | 798.23651 | 804.22833 |
Data taken at the end of the test:
9:35:53 PM | 817.56586 | 84.038 | 817.40479 | 817.7196 |
9:35:58 PM | 817.63971 | 84.038 | 817.35712 | 817.86035 |
9:36:03 PM | 817.72827 | 84.038 | 817.52637 | 817.90094 |
The advantage of having both readings in a leak test is that it is easy to evaluate the effect of temperature on pressure in the closed system. Using the Gay-Lussac's law (P1/T1 = P2/T2, where P is the pressure T is the absolute temperature), it is possible to determine if there is indeed a leak.
The CPG1500 integrated data logger allows storage of up to 50 readings per second. The log files can be downloaded for both the leak test and daily monitoring. Data can be downloaded in CSV format on a computer or by using the app. Remote monitoring of these tanks can be achieved by simply connecting and downloading data.