ISA Certified Control Systems Technician (CCST) program

CCST

Certified Control System Technicians (CCSTs) calibrate, document, troubleshoot, and repair/replace instrumentation for systems that measure and control level, temperature, pressure, flow, and other process variables.

CCST question

In order to provide a sample to a gas chromatograph or other extractive field analytical instrument at the proper temperature, pressure, flow, or concentration to make it most compatible with the analyzer, the sample should pass through a ____________ prior to entering the analyzer chamber.

A. glass capillary tube
B. sample probe calibration system
C. sample conditioning system
D. smooth-walled pipe

CCST Answer

The correct answer is C, “sample conditioning system.” Answers A and C are items not generally associated with extractive field analyzers. Capillary tubes are used for collecting small samples (water, for instance) from a larger container. There are special capillary tubes that can be used in the analyzer chamber of a gas chromatograph, but they are not constructed from glass. Smooth-walled pipe is important for reducing friction losses in piping systems.
A sample probe calibration system is important to the overall function and maintenance of an extractive field analyzer. However, these systems are not used to prepare the sample for analysis, but rather to provide a mechanism to verify and maintain analyzer performance.
A sample conditioning system can contain devices, such as filters, demisters, flow regulators, and heaters. Sample conditioning systems are used to bring the sample to the ideal process conditions for accurate measurement in the analyzer itself. The sample conditioning system can be a key maintenance item in an analyzer system, since each device needs to be calibrated, cleaned, etc.

 

Reference: Goettsche, L.D. (Editor), Maintenance of Instruments and Systems, Second Edition, ISA, 2005.