CHAPTER 2 S ENSING AND S AMPLING S TRATEGIES M. Z. Atashbar S. Krishnamurthy 1. INTRODUCTION Sensors are widely used in many domestic, industrial, and military applications as well as remote sensing of various chemical vapors and chemical warfare agents. The signal obtained from the sensor is analog, and hence data acquisition and interpretation of information are important tasks. Data acquisition systems are used to transfer real-world signals to a computer. These signals are further processed in a computer to extract specific information about the parameter being sensed. This chapter provides an in- troduction to sensing parameters, sensor fundamentals, sensor testing and calibration methods, repeat- ability and stability of sensors, as well as some of the sensing and sampling strategies that are commonly used in single- and multi-sensor environments. The sensing strategies presented here are intended to introduce a few of the commonly used strategies and by no means are comprehensive. 2. SENSING PARAMETERS A number of parameters are used to characterize the performance of a sensor, including sensitivity, selectivity, response time, recovery time, saturation resolution, and noise. These parameters are described briefly in this section. 39