The Constant Rate syringe is a semi-automatic, push button syringe. It delivers identical volumes and is set by a micrometer-like setting device, permitting the user to dial in the desired volume in increments as small as 0.05¬µl. Setting is held constant by a tightened knurled lock ring. The plunger is spring-driven and ejects the sample rapidly, and forcefully, and at a constant rate. This syringe is typically used in conjunction with total organic carbon analyzers to monitor waste water and environmentally sensitive water resources. Semi-conductor manufacturers use this syringe for sampling process water.