Automatic Sampling Control & Calibration Module

An ASCM-10 unit is designed for customers who test multiple CO₂ sampling points with their gas analyzer system and to conveniently perform analyzer calibration + validation functions. A standard ASCM-10 allows selection of up to 5 gas sample lines (channels). This can be increased to 10 channels by installing an add-on sampling package (p/n CH-10).

The ASCM-10 accepts vaporized Liquid CO₂ (LCO₂) gas streams from sampling cylinders or 1/16 to 1/4” passivated lines that have been pressure controlled down to between 40 - 80 psig. All internal components of an ASCM-10 and connective hardware are comprised of rugged, reliable, passivated materials (including PTFE-solenoid valves) to meet ISBT guidelines for sampling and testing of beverage-grade LCO₂.

Sample lines or cylinders are connected to back-panel bulkhead fittings after passing through 0.5um in-line filters. Control of sample line (channel) selection is made either manually or placed under automatic “external = EXT” control by a front-panel 12 position rotary switch. In the EXT mode, a TTL digital logic transition from logic 1 to 0 (+5V to 0V) from a computer - will open the appropriate (NC) solenoid valve. The outlet of all channel solenoid valves is connected to a common, low-dead volume manifold. The gas within this manifold is then directed to both a “purge” solenoid line and a passivated, pressure regulator set for 20 psig delivery. The line-purged, 20 psig sample stream is then sent to all analyzers.

To rapidly transport a representative sample to all analyzers, the ASCM-10 is equipped with “Purge Control’. A toggle switch selects “Purge On/Off” and “EXT” options. An adjustable flowmeter allows the purge flow to be set between 1 - 2 LPM. In the “EXT” position, a TTL logic transition from an external PC is used to open or close the purge line solenoid.

ALI recommends use of either 1/8 or 1/16” Sulfinert passivated lines to both minimize line purging times and the surface area of hardware that a sample contacts.This strategy minimizes trace impurity adsorption and the resulting errors that would result in a trace impurity measurement.The ID of transfer tubing depends on required line length and curvatures experienced between the sample source and analyzers.

For interfacing a LCO₂ sampling point to a transfer line, ALI recommends use of our passivated LCO₂ vaporizer - pressure regulator (p/n VPR-120) in a “straight” configuration. For 1L LCO₂ sampling cylinders, we recommend a VPR-120 in its 90^o configuration. A VPR-120 efficiently vaporizes an LCO₂ source and properly regulates the pressure to between 40 - 80 psig for transport to the ASCM-10 and analyzer system.

To perform analyzer calibration or periodic validation checks the ASCM-10 is equipped with 2 calibration controllers. A calibration controller allows you to direct either the channel-selected sample, “zero” or “span calibration” gas to a specific analyzer (e.g.a THC analyzer). These functions can either be performed manually or under external PC control by simply setting the controller knob to the “E” position.

Shown below is an ASCM-10 unit, which can either be bench or rack mounted. Please contact us if you have any questions or require a quotation.

ASCM-10 Automatic Sampling Control & Calibration Module