- M
- Symbol for mega (million).
-
- m
- Symbol for meter and milli- (one thousandth).
-
- Magnetic Sensor
- Sensors that are magnetically controlled by a small
rotor closely positioned in front of the active sensing
face. MLFK type of magnetic encoders has been designed to
provide linear position information with <20 micrometers
resolution. Short and medium distance applications are
preferred. Advantages: non contact length measuring, no
moving parts, housing sealed to IP67. MDFK type of
magnetic encoder consists of a magnet rotor and a
magneto-resistive sensor. May be used just like a standard
incremental encoder. Advantages: easy installation, low cost
alternative to standard encoders, up/down recognition
possible.
-
- Mains
- Source of electrical power, normally the electricity supply system.
-
- Mains Frequency
- Electricity ac supply frequency: 60 Hz in US , 50 Hz in UK.
-
- Maintained Contact Switch
- designed for applications requiring sustained contact after plunger has been
released, but with provision for resetting.
-
- Man Machine Interface (MMI)
- Also known as human machine interface. The communication between the
computer system and the people who use it.
-
- Manual Mode
- Controller does not adjust output for changes in SP or PV. Instead, the user
sets the output.
-
- Master
- A device that transmits a set point signal to other
controlling devices called remotes.
-
- Maximum Error Limit
- Maximum difference between measured and reference
position over one 360° rotation over the full operating
temperature (range).
-
- Maximum Excitation
- The maximum value of supply voltage or current that can be applied to the
sensor at room conditions without causing damage or performance degradation
beyond specified tolerances.
-
- Maximum Installation Torque
-
-
| Stainless Steel
Thread |
M4 |
1.8 Nm |
| M5 |
2 Nm |
| M8 |
10 Nm |
| M12 |
20 Nm |
| M18 |
55 Nm |
| Brass Nickel Plated
Thread |
M8 |
7 Nm |
| M12 |
15 Nm |
| M18 |
40 Nm |
| M30 |
200 Nm |
|
Polybutylenterephthalate Thread |
M12 |
1.5 Nm |
| M18 |
3 Nm |
| M30 |
15 Nm |
(Reduce torque values by 30% at the sensor’s
face) The above data is valid for installations using the
mounting nuts supplied with the sensor.
-
- Maximum Load Current
- The maximum amount of current that can flow through a
sensor and not cause sensor failure.
-
- Maximum Load Impedance
- The largest load that the output device can operate.
Usually specified in ohms.
-
- Maximum Output Impedance
- The largest load that the output device can drive while
providing the full range of output.
-
- Maximum Switching Current
- The maximum permissible load current passed through the
sensor.
-
- Measurand
- A physical quantity, property, or condition which is measured (e.g.,
pressure, temperature, flow, level, acceleration).
-
- Mechanical Life
- Life of a switch with no (or a negligible) electrical load, and a specified
combination of actuation, environment and criterion of failure. Mechanical life
usually is limited by the life of the switch's flexing parts and bearing
surfaces.
-
- Media compatibility
- Ability to operate with a specified media carrying pressure (e.g., salt
water).
-
- Metre
- The SI fundamental unit of length, equal to 1.093 yards. (Meter in US.)
-
- Microvolt
- One one millionth of a volt
-
- Migration, Contact Material
- A net transfer of material from one contact to the mating contact as a
result of switching an electrical load. It usually takes the form of a needle,
cone or mound or one contact face and a corresponding pit in the surface of the
mating contact.
-
- mil
- One thousandth of an inch, or 0.001 inches in decimal
form.
-
- Milliampere (mA)
- One thousandth of an ampere.
-
- Millivolt (mV)
- One one thousandth of a volt.
-
- Minimum Life
- An exact term only when applied to a specific group of tested switches,
meaning the lowest life figure obtained from the test of that group of switches.
-
- Minimum Load Resistance
- The voltage drop across the load resistance is
proportional to the current, using a sensor with current
output. To ensure a proper functioning of the output stage
do not exceed the maximum permissible load resistance as
stated in the data sheet.
-
- Minutes Per Repeat
- Time between each repeat of proportional action by reset.
-
- Miscible
- Capable of being mixed.
-
- Mlbs
- Shorthand for 1,000 pounds of mass. The subscript m is commonly dropped and
an "s" is added indicating plurality. The capital M is from the Roman numeral
system where M is the multiplier x1000. This should not be confused with the "M"
commonly seen in the metric system which is Mega for million.
-
- MMBtu
- One million BTUs. The M's are from the Roman numeral system where M is a
multiplier of 1000. Therefore MM is 1,000 x 1,000 or 1,000,000. The M should not
be confused with the metric or SI systems where M is mega for million.
-
- MMI
- Man Machine Interface (aka HMI or human machine interface). Refers to the
software that the process operator "sees" the process with. An example MMI
screen may show you a tank with levels and temperatures displayed with bar
graphs and values. Valves and pumps are often shown and the operator can "click"
on a device to turn it on, off or make a setpoint change. Examples are
Intellution's FIX DMACS, Wonderware's Intouch, Genesis's ICONICS, TA
Engineering's AIMACS, and Intec's Paragon.
-
- Modbus
- An industrial networking system that uses peer-to-peer communications.
-
- Mode
- Auto, manual, or remote. In auto mode the controller calculates the output
based its calculation using the error signal (difference between setpoint and
PV). In manual mode, the user sets the output. In remote, the controller is
actually in auto but gets its setpoint from another controller.
-
- Modular
- Form of construction in which hardware or software units, often with
differing functions, are quickly interchangeable.
-
- Momentary Short Circuit
- A switch with contacts that return from operated condition to normal
condition when actuating force is removed. Unless otherwise stated, all switches
in this catalog are momentary.
-
- Momentary Short Circuit Protection
- Output circuit protection designed to protect the output device from damage
due to a temporary (1-3 sec.) short circuit or until an external fuse can
interrupt current.
-
- Momentary Switch
- A switch with contacts that return from operated condition to normal
condition when actuating force is removed. Unless otherwise stated, all switches
in this catalog are momentary.
-
- Multiplex Operation
- In this mode two sensors may be mounted without any
spacing, since they operate alternately. The response and
release time of the specific sensors is therefore doubled.
The connecting "control" wire must be connected to ground,
if the sensor is not multiplexed.
-
- Multiplexing
- Where each signal is switched in turn to a single analog-to-digital
converter. As opposed to where one A-D converter is used for each signal in
simultaneous sampling.
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