User`s manual
Lake Shore MTD Series Cryotest System User’s Manual
Glossary of Terminology A-1
APPENDIX A
GLOSSARY OF TERMINOLOGY
absolute zero. The temperature of –273.15 °C, or –459.67 °F, or 0 K, thought to be the temperature at which molecular
motion vanishes and a body would have no heat energy.
1
accuracy. The degree of correctness with which a measured value agrees with the true value.
2
electronic accuracy. The accuracy of an instrument independent of the sensor.
sensor accuracy. The accuracy of a temperature sensor and its associated calibration or its ability to match a
standard curve.
Alumel™. An aluminum-nickel alloy which comprises the negative lead of a Type K thermocouple.
American Wire Gage (AWG). Wiring sizes are defined as diameters in inches and millimeters as follows:
AWG Dia. In. Dia. mm AWG Dia. In. Dia. mm AWG Dia. In. Dia. mm AWG Dia. In. Dia. mm
1 0.2893 7.348 11 0.0907 2.304 21 0.0285 0.7230 31 0.0089 0.2268
2 0.2576 6.544 12 0.0808 2.053 22 0.0253 0.6438 32 0.0080 0.2019
3 0.2294 5.827 13 0.0720 1.829 23 0.0226 0.5733 33 0.00708 0.178
4 0.2043 5.189 14 0.0641 1.628 24 0.0207 0.5106 34 0.00630 0.152
5 0.1819 4.621 15 0.0571 1.450 25 0.0179 0.4547 35 0.00561 0.138
6 0.1620 4.115 16 0.0508 1.291 26 0.0159 0.4049 36 0.00500 0.127
7 0.1443 3.665 17 0.0453 1.150 27 0.0142 0.3606 37 0.00445 0.1131
8 0.1285 3.264 18 0.0403 1.024 28 0.0126 0.3211 38 0.00397 0.1007
9 0.1144 2.906 19 0.0359 0.9116 29 0.0113 0.2859 39 0.00353 0.08969
10 0.1019 2.588 20 0.0338 0.8118 30 0.0100 0.2546 40 0.00314 0.07987
ambient temperature. The temperature of the surrounding medium, such as gas or liquid, which comes into contact with
the apparatus.
1
ampere. The constant current that, if maintained in two straight parallel conductors of infinite length, of negligible circular
cross section, and placed one meter apart in a vacuum, would produce between these conductors a force equal to
2 x 10
–7
newton per meter of length.
2
This is one of the base units of the SI.
ampere-turn. A MKS unit of magnetomotive force equal to the magnetomotive force around a path linking one turn of a
conducting loop carrying a current of one ampere; or 1.26 gilberts.
ampere/meter (A/m). The SI unit for magnetic field strength (H). 1 ampere/meter = 4π/1000 oersted ≈ 0.01257 oersted.
analog controller. A feedback control system where there is an unbroken path of analog processing between the
feedback device (sensor) and control actuator (heater).
analog data. Data represented in a continuous form, as contrasted with digital data having discrete values.
1
analog output. A voltage output from an instrument that is proportional to its input. From an instrument such as a digital
voltmeter, the output voltage is generated by a digital-to-analog converter so it will have a discrete number of voltage
levels.
anode. The terminal that is positive with respect to the other terminal when the diode is biased in the forward direction.
2
Anode Cathode
+–
asphyxiant gas. A gas which has little or no positive toxic effect but which can bring about unconsciousness and death
by displacing air and thus depriving an organism of oxygen.
autotuning. In Lake Shore Temperature Controllers, the Autotuning algorithm automatically determines the proper
settings for Gain (Proportional), Reset (Integral), and Rate (Derivative) by observing the time response of the system
upon changes in setpoint.
B. Symbol for magnetic flux density. See Magnetic Flux Density.
bar. Unit of pressure equal to 10
5
pascal, or 0.98697 standard atmosphere.
baud. A unit of signaling speed equal to the number of discrete conditions or signal events per second, or the reciprocal
of the time of the shortest signal element in a character.
2
bel (B). A dimensionless unit expressing the ration of two powers or intensities, or the ratio of a power to a reference
power, such that the number of bels is the common logarithm of this ratio.
1
bifilar windings. A winding consisting of two insulated wires, side by side, with currents traveling through them in
opposite directions.
1
bit. A contraction of the term “binary digit”; a unit of information represented by either a zero or a one.
2
BNC. Bayonet Nut Connector.