The crucial step in chromatographic analysis of dissolved gases in transformer oil is to take an oil sample, which should be representative enough. The ideal sampling method should meet the following conditions to prevent the loss of dissolved gases in the oil.
(1) The glass syringe used has good tightness.
(2) During sampling, completely isolate the air and do not let air escape or inhale after sampling.
(3) The material is chemically stable and not easily damaged, making it easy to store and transport.
(4) When taking oil samples, a 100ml full glass syringe is generally used.
(5) Before sampling, clean and dry the syringe thoroughly. The plunger of the syringe should be able to slide freely without any jamming.
(6) Oil should be sampled from the sampling valve at the bottom of the equipment.
(7) The residual oil in the sampling valve should be removed as much as possible, and the dirt around the valve body should be wiped clean.
(8) The sampling connection method is reliable, and the connection system has no oil or gas leakage defects.
(9) Before sampling, efforts should be made to exhaust the air in the sampling container and connecting system.
(10) During sampling, the oil sample shall flow into the container smoothly without impact, splash or foam
(11) After taking the oil sample, close the oil drain valve, remove the syringe, seal the port, label it, and perform chromatographic analysis as soon as possible.
