Values for sensors

Atm in pa

101325 Pa

Bar in pa

10^5 Pa

Thermal coef of constantan

2.10^-5 /K

Torque applicable with fingers

10^-3 Nm

Cycles with wirewound potentiometer

1–10 million

cycles for single 10um wire

10^5

Constantan resistivity

1 uohmm

Conductive plastic resistivity

1 mohmm

Germanium resistivity

1 ohmm

Resistance of plastic potentiometer

1 kohm 100 kohm

Max Power to plastic potentiometer

1 Watt

Temperature coef of plastic potentiometer

-10^-4 /K

RH influence of plastic potentiometer

10^-4 /RH

Scan speed of plastic potentiometer

50 Hz

Order of magnitude elongation of strain gauges

1–3%

Poisson’s ratio of metals

0.3

Max T° for strain gauges

400C

cooled dynamic torque brush max RPM

100 000

Typical resistance of strain gauges

120-350 ohm

Good λ vs L ratio for strain gauges

10

6 mm gauge cutoff frequency

100 kHz

Sound speed in steel

6 km/s

% accuracy needed to measure R change of 10^-3 in Wheatstone

0.1%

Gauge factor metallic Vs semiconducting of strain gauges

2 vs 200

Sensitivity of Semi gauges strain output / input

60 mV/V

Pt100 sensor range

13K - 900C

Pt100 dR/dT

0.385 ohm/c

R(100C)/R(0C)

1.385

Copper heat thermal conduction

400 W/m·K

Accuracy of PT100 resistance

10^-3 K

Temperature coef Semi vs Metals

10x

Typical value of B for Semi NTC

4000 K

Range of NTC Temperature

-100 150 C

Current in pirani gauge

10-100 mA

Change in wire resistance of pirani

10%

Vibrating wire frequency (flow)

250 Hz

max measurement Frequency of vibrating wire

10 kHz

Power consumption of Thomas flowmeter

1 kW

Laub flowmeter debit

5-3000 L/h

mu0

4π 10^-7 H/m

Villary effect change of permeability

20%

Upper operating frequency air coil

1–10 MHz

Upper operating frequency Ferromagnetic coil

20 kHz

Inductor measure sheet thickness

10 um – 5 mm

Resolution / range / temp coef of Wiedmann effect

1um 25-7600mm 15ppm/C

% flux lines in secondary core pressductor

20%

Tension frequence réseau

230V 50Hz

Airplane frequency synchro

400Hz

LVDT T range

4K - 600°C

Excitation frequency of eddy current

1MHz

Min thickness of plate for eddy

3 delta

min diameter of plate for eddy

3 times larger

Min RPM for coil induction

30RPM

Permittivity of vacuum ε₀

8.854.10^-12 F/m

Precision of C sensor with tooths

1um

εr needed for level ε sensor (grains)

2

Range of chnage of C for person detection

pF → nF

Capacitive detector min plate size

1.3

εr water

80

εr air variation between 1→ 100 atm

5%

C sensor temperature range

10k – 250k

Quartz max T / P / piezo coef

550°C / 10^12 ohmm / 3pC/N

Polling electric field

10^6 V/m

PZT permittivity / snesitivity

εr > 300 / 200pC/N

Frequencies for piezo sensors

>10KHz

Range / output Z/ C / max deformation PZT

0→1MN / 10^14 ohm / 10-700pF / 15um

Shock piezo f and min g tolerance

> 1KHz / 500 g

Cross axis sensitivity variation in % for piezo accelerometers

< 1%

Accelerometer mass vs tested mass ratio %

10%

Coaxial cappa / m

100 pF/m

mu silicon / InSb / InAs

0.13 / 8 / 2.5 m²/Vs

L/W ratio for hall probe

2

Hall probe max frequencies

1 MHz

Magnetic effect in Tesla of Earth/ cards / magnets / motor / IRM

10^-5 10^-3 – 10^-2 – 1 - 5 T

Max sensitivity hall probe

10^-15 T

Surface needed for 5 hall probes

0.001 mm²

Hall probe max shock/ vibration

50g 2kHz

Max resistivity of fluid for magnetic flowmeter

10^4 ohmm

Copper constantan delta S

40 uV/K

Max thermocouple T

2200 C

Cu–CuO thermocouple ΔS

1000 uV/K

Surface rugosity leading to specular/diffuse

lambda / 4

Far field zone equation

L > D²/4 lambda

Frequencies: infra sound / sound / ultra sound

20 Hz / 20 kHz

Speed of sound in air/water/steel

331 m/s – 1.4 km/s – 6 km/s

microwave lambda / f

1mm / 1m 300MHz / 300GHz

light lambda / f

400 / 700 nm 4.3-7.5 10^14 Hz

Speed of light

3.10^8

Ultrasound frequencies for fluid flowmeter

0.4 – 4 MHz

Transmission coef for air–water air–steel water–steel

10^-3 10^-5 0.15

Sonar thickness lower bound

0.3 mm

Microwave applications range of frequencies

300 MHz – 300 GHz

Z₀ vacuum

377 ohm

EM epsilonr reflection bounds huge ok bad

10 / 2

Power of small Gunn oscillator

10 – 20 mW

Cement reflection specular/ diffuse freq

6GHz / 24GHz

Ratio wavelength to size of blocking light object (QEI)

10 x

Infrared wave length light

10 um

Thickness of semiconduct plastics

20-100um

Typical time cst of piezo with multimeter and coax

10^-3s