M: Mega; one million. When referring to memory capacity, two to the twentieth power (1,048,576 in decimal notation).
Machine Language: Instructions that are written in binary form that a computer can execute directly. Also called object code and object language.
Maximum Operating Temperature: The maximum temperature at which an instrument or sensor can be safely operated.
Maximum Power Rating: The maximum power in watts that a device can safely handle.
Measurand: A physical quantity, property, or condition which is measured.
Megahertz (MHz): 1,000,000 Hertz; a unit of frequency.
Megasamples per second (MS/s): A sample rate unit equal to one million samples per second.
Melting Point: The temperature at which a substance transforms from a solid phase to a liquid phase.
Mica: A transparent mineral used as window material in high-temperature ovens.
Microamp: One millionth of an ampere, 10-6 amps, µA.
Microcomputer: A computer which is physically small. It can fit on top of or under a desk; based on LSI circuitry, computers of this type are now available with much of the power currently associated with minicomputer systems.
Micron: One millionth of a meter, 10-6 meters.
Microsecond (ms): A unit of time equivalent to 0.000001 seconds.
Millisecond (ms): A unit of time equivalent to 0.001 seconds.
Microvolt: One millionth of a volt, 10-6 volts.
Mil: One thousandth of an inch (.001").
Milliamp: One thousandth of an amp, 10-3 amps, symbol mA.
Millimeter: One thousandth of a meter, symbol mm.
Millivolt: Unit of electromotive force. It is the difference in potential required to make a current of 1 millampere flow through a resistance of 1 ohm; one thousandth of a volt, symbol mV.
Minor Scale Division: On an analog scale, the smallest indicated division of units on the scale.
Modem: Modulator/Demodulator. A device that transforms digital signals into audio tones for transmission over telephone lines, and does the reverse for reception.
Monostable: Circuit with two states. Only one state is stable.
MOS: Metal Oxide Semiconductor. Technology used in the manufacture of semiconductors.
MOSFET: Metal-Oxide-Silicon-Field-Effect-Transistor. See FET.
Motherboard: The pc board of a computer that contains the bus lines and edge connectors to accommodate other boards in the system. In a microcomputer, the motherboard contains the microprocessor and connectors for expansion boards.
Mounting Error: The error resultant from installing the transducer, both electrical and mechanical.
MSD (Most-Significant Digit): The leftmost digit of the display.
Multiples and sub-multiples of Units:
Muliplication Factor Prefix Symbol
1012 tera T
109 giga G
105 mega M
103 kilo k
102 hecto h
101 deca da
10-1 deci d
10-2 centi c
10-3 milli m
10-6 micro µ
10-9 nano n
10-12 pico p
10-15 femto f
10-18 atto a
Multiplex: A technique which allows different input (or output) signals to use the same lines at different times, controlled by an external signal. Multiplexing is used to save on wiring and I/O ports.
Multivibrator: A building block in which the output is either High or Low. There are three foms of multivibrator: Monostable, bi-stable and astable. The monostable has only one stable state, the bi-stable has two stable states and the astable is free-running (no stable states).