Liquid sampling

A liquid sampler, comprising:

• a liquid inlet connectable to a liquid circuit containing a liquid to be sampled;
• a sampling reservoir for collecting a liquid sample, wherein the sampling reservoir comprises a removable container;
• a sampling pump connected to the liquid inlet and operable to extract a discrete amount of liquid from the liquid inlet and to discharge the discrete amount of liquid into the sampling reservoir, the sampling pump having a reciprocally displaceable plunger disposed in a sample chamber shaped to accommodate a head of the plunger, the plunger displaceable between at least two positions, being a predefined measuring position in which the volume of the sample chamber is selectively predetermined and an extended position in which the volume of the sample chamber is at a minimum, the sampling pump having an actuator driving the plunger between the at least two positions;
• and
• a controller controllably connected to the actuator, the controller programmed to drive the actuator at predefined intervals in order to take liquid samples at predefined intervals;
• wherein the liquid sampler includes a hermetically sealed enclosure into which its components are mounted, said hermetically sealed enclosure including pressurization means operable to pressurize the inside of the hermetically sealed enclosure to maintain a positive pressure inside the hermetically sealed enclosure, thereby to minimize a risk of sample contamination;
• and
• wherein the liquid sampler includes a container sensor operable to sense when a removable container is appropriately received inside the sealed enclosure, the controller programmed to inhibit taking liquid samples when the container sensor does not sense a container in the enclosure.