VICI Metronics’ Dynacal Permeation Tubes are small, inert capsules containing a pure chemical compound in a two-phase equilibrium between its gas phase and its liquid or solid phase. At a constant temperature, the device emits the compound through its permeable portion at a constant rate. Accurate, stable concentrations range from PPB to high PPM. The purpose of a calibration gas standard is to establish a reference point for the verification of an analysis. Permeation tube rates can be certified using standards traceable to NIST by the most basic and accurate laboratory procedure–measuring the gravimetric weight loss over a known period of time at a known temperature. Devices are typically inserted into a carrier flow to generate test atmospheres for calibrating gas analyzer systems, testing hazardous gas alarms, or conducting long-term studies of effects on materials or biological systems. Applications include laboratories, environmental, semiconductor, petrochemical, and food & beverage. –