Lexical analyzer Programs that perform lexical analysis are called lexical analyzers or lexers. In computer science, lexical analysis, lexing or tokenization is the process of converting a sequence of characters (such as in a computer program or web page) into a sequence of tokens (strings with an assigned and thus identified meaning). A program that performs lexical analysis may be termed a lexer, tokenizer, or scanner, although scanner is also a term for the first stage of a lexer. A lexer is generally combined with a parser, which together analyze the syntax of programming languages, web pages, and so forth. Lexical analysis is the first phase of a compiler. It takes the modified source code from language preprocessors that are written in the form of sentences. The lexical analyzer breaks these syntaxes into a series of tokens, by removing any whitespace or comments in the source code. LEXICAL ANALYSIS is the very first phase in the compiler designing. A Lexer takes the modified s

  Logic analyser Logic analyzers are widely used to develop and debug electronic logic circuits - they display traces of multiple logic channels and reveal the circuit operation. A logic analyzer is an electronic instrument that captures and displays multiple signals from a digital system or digital circuit. A logic analyzer may convert the captured data into timing diagrams, protocol decodes, state machine traces, assembly language, or may correlate assembly with source-level software. Logic analyzers have advanced triggering capabilities, and are useful when a user needs to see the timing relationships between many signals in a digital system. Logic analyser types Although development of these test instruments is on-going and new variants are constantly being launched and many technology innovations are being achieved, there are some main categories into which most logic analyzers can be split: Modular logic analyzers   This type of logic analyser is probably what may be thought of a

  Electron microprobe An electron microprobe (EMP), also known as an electron probe microanalyzer (EPMA) or electron micro probe analyzer (EMPA), is an analytical tool used to non-destructively determine the chemical composition of small volumes of solid materials. It works similarly to a scanning electron microscope: the sample is bombarded with an electron beam, emitting x-rays at wavelengths characteristic to the elements being analyzed. This enables the abundances of elements present within small sample volumes (typically 10-30 cubic micrometers or less) to be determined, when a conventional accelerating voltage of 15-20 kV is used. The concentrations of elements from lithium to plutonium may be measured at levels as low as 100 parts per million (ppm), material dependent, although with care, levels below 10 ppm are possible. The ability to quantify lithium by electron probe microanalyzer. The technique is commonly used for analyzing the chemical composition of metals, alloys, ceram

  Differential analyser  The differential analyser is a mechanical analogue computer designed to solve differential  equations by integration, using wheel-and-disc mechanisms to perform the integration. It was one of the first advanced computing devices to be used operationally. The original machines could not add, but then it was noticed that if the two wheels of a rear differential are turned, the drive shaft will compute the average of the left and right wheels. A simple gear ratio of 1:2 then enables multiplication by two, so addition (and subtraction) are achieved. Multiplication is just a special case of integration, namely integrating a constant function.  Differential analyzer, computing device for solving differential equations. Its principal components perform the mathematical operation of integration  A differential analyzer is a complicated arrangement of rods, gears, and spinning discs that can solve differential equations of up to the sixth order. It is like a digital com

  Bus analyser A bus analyzer is a type of a protocol analysis tool, used for capturing and analyzing communication data across a specific interface bus, usually embedded in a hardware system. The bus analyzer functionality helps design, test and validation engineers to check, test, debug and validate their designs throughout the design cycles of a hardware-based product. It also helps in later phases of a product life cycle, in examining communication interoperability between systems and between components, and clarifying hardware support concerns. A bus analyzer is designed for use with specific parallel or serial bus architectures. Though the term bus analyzer implies a physical communication and interface that is being analyzed, it is sometimes used interchangeably with the term protocol analyzer or Packet Analyzer, and may be used also for analysis tools for Wireless interfaces like wireless LAN (like Wi-Fi), PAN (like Bluetooth, Wireless USB), and other, though these technologies

  Automatic Analyzer Complete automation will lead to human prohibition in pharma industries. “One machine can do the work of fifty ordinary men, no machine can do the work of one extraordinary man” automation as the use of combinations of mechanical and instrumental devices to replace, refine, extend or supplement human effort and facilities in the performance of a given process, in which at least one major operation is controlled without human intervention, by a feedback mechanism. Benefits of Automation Faster analyses up to 120 samples per hour. Up to 300 samples can be analyzed in batch. Automatic data recording and preparation Being a closed system, automation reduces contamination, for e.g., from atmospheric gases. Greater accuracy and reproducibility of results as all samples are subject to same processes. Smaller sample and reagent volumes which reduces cost. Automatic range changing, drift control and automatic sample preparation. Need for automation The partial or complete r

  Automated analyzer An automated analyser is a medical laboratory instrument designed to measure different chemicals and other characteristics in a number of biological samples quickly, with minimal human assistance. These measured properties of blood and other fluids may be useful in the diagnosis of disease. Basic approaches to automated analysers Continuous flow analysers Centrifugal analysers Discrete auto analysers Dry chemical analysers Continuous flow analyzers (nearly out of date) Liquids (reagents, diluents and samples) are pumped through a system of continuous tubing. Samples are introduced in a sequential manner, following each other through the same network. Series of air bubbles at regular intervals serve as separating and media. The internal diameter of the tubing and the rate of flow determine the volumes of sample prior to mixing with the reagents and the turn around time of the result. -An oil heating bath is used to promote color development or the completion of enzy

Positive displacement flow meter Introduction A positive displacement meter is a type of flow meter that requires fluid to mechanically displace components in the meter in order for flow measurement. Positive displacement flow meters measure the volumetric flow rate of a moving fluid or gas by dividing the media into fixed, metered volumes.  Positive displacement flow meters are very accurate and have high turndown. They can be used in very viscous, dirty and corrosive fluids and essentially require no straight runs of pipe for fluid flow stream conditioning though pressure drop can be an issue. They are widely used in the custody transfer of oils and liquid fluids (gasoline) and are applied on residential home natural gas and water metering. A diaphragm meter, with which most homes are equipped, is an example of a positive displacement meter. This type of meter is appealing in certain custody transfer flow applications where it is critical that the metering be functional in order for

  H2S Analyzers Questions & Answers 1. Which of the following is not an advantage of electrochemical cells used for analysis of H2S? a) Portable battery operated instrument b) Pocket sized instrument c) No pumps are needed d) No interference from background gases Answer: d 2. Which of the following methods are mainly used in combustible gas detection equipment? a) Lead acetate tape staining method b) Solid state sensor c) Gold film sensor d) Electrochemical cells Answer: b 3. Which of the following is not an advantage of solid state sensor used for analysis of H2S? a) No sampling system b) It can be used in conditions involving vibration c) It can be used in corrosive atmosphere d) No interference from background gases Answer: d 4. Which is the compound that forms the stain in Lead Acetate Tape Staining method used for the analysis of Hydrogen Sulphide and what is the colour of the stain? a) Lead Sulphide, red colour b) Lead Sulphide, brown colour c) Hydrogen acetate, white colour