The Buck Automatic Calibration System (ACS) allows for automatic, unattended recalibration when using a Buck GC equipped with the TO-14 Air Concentrator for ambient air analysis.
Under control of the PeakSimple software included with the GC, the ACS can make dilutions of the customer-supplied standard gas and Zero Air at ratios of 10,000 to 1. For example, if the standard EPC on the TO-14 GC is set to 50psi, a 100ppm standard gas flows through the restrictor at a rate of 100 milliliters per minute; the Zero Air flows at a rate of 1,000 milliliters per minute. This produces a 10ppm diluted gas, which is sampled into the TO-14 Air Concentrator by the vacuum pump (supplied with the TO-14 Air Concentrator).
By manipulating both the EPC pressure and time, the 100ppm standard can be diluted over a 10,000 to 1 concentration. For example, let's say you've decided to use 300 seconds as the length of time the vacuum pump