Instant Notes: Analytical Chemistry

Section H – Sensors, automation and computing

H3 COMPUTER CONTROL AND

DATA COLLECTION

A digital computer consists of four principal hardware components.

(i) The central processing unit(CPU), which includes the microprocessor

integrated circuit chip, registers for the temporary storage of data, and a

high frequency clockto synchronize all operations. Clock frequencies,

which determine computing speed, are steadily increasing and are

currently approaching or exceeding 1.5 GHz.

(ii) Random access memory(RAM) for the temporary storage of current

programs and data, read only memory(ROM) for the storage of data for

reference and frequently used routines, and long term memory on magnetic

and optical disks (CD and DVD), capable of storing from one or more

megabytes (Mbytes) of information up to several gigabytes (Gbytes).

(1 byte, or 8 bits (binary digits) defines an alphanumeric character.)

(iii)Input and output(I/O) devices, i.e. keyboards, VDU screens, printers,

plotters, scanners, instrument interfaces, modems and digital cameras.

(iv) Parallel or serial transmission lines (buses) for internal and external transfer

of program instructions and data.

Computers can be programmed to set and monitor instrument parameters to

ensure stable and reproducible operation. Groups of parameters can be stored

and retrieved as standard methods for routine use. Self-diagnosticroutines to

test the condition of instrument components and locate faults are a common

feature of many computer−instrument software packages.

Computer–
instrument
interfacing

Microprocessors
and
microcomputers

Key Notes

Digital computers consist of hardware and software components that use

binary code for data and word processing. The microprocessor, an

integrated circuit chip that performs all the operations and computations,

is at the heart of a microcomputer, which also includes various forms of

memory for program and data storage, and input/output devices.

Computer control of operating parameters and the digitizing of analog

detector signals for storage and processing are important aspects of

interfacing computers with analytical instruments.

The electronic transfer of data and other information between

instruments and laboratories is facilitated by connecting them together in

a network. The analytical work and overall management of one or more

laboratories can be controlled and monitored through the use of

specifically designed software packages.

Related topic Data enhancement and databases (H4)

Microprocessors and

microcomputers

Networking and

laboratory

management

Computer−instrument

interfacing