Emcam21 by American Technical Publishers

Application — Thermistors The resistance of NTC thermistors decreases as the temperature increases. NTC thermistors are the most common type of thermistors in use. The resistance of PTC thermistors increases as the temperature increases. Thermistors are available with a variety of resistance values. The resistance of thermistors is commonly specified at a temperature of 25°C (77°F) for ease of testing before they are placed into a heating or cooling application. Although thermistors are available with a variety of resistance values, standard NTC thermistors rated at 25°C (77°F) include the following resistance values: 2 kΩ, 3 kΩ, 5 kΩ, 10 kΩ, 30 kΩ, 50 kΩ, and 1 MΩ. Changes in thermistor resistance are not linear with temperature changes. Manufacturers provide charts showing specific resistances at each temperature above and below the thermistor rating (typically 25°C). See Temperature vs. Resistance — 2000 Ω NTC Thermistor.

TEMPERATURE vs. RESISTANCE—2000 Ω NTC THERMISTOR Temperature °F –40.00 –22.00 –4.00 14.00 32.00 41.00 59.00 77.00 95.00 113.00 131.00 149.00 167.00 185.00 203.00 212.00

°C –40.00 –30.00 –20.00 –10.00 0.00 5.00 15.00 25.00 35.00 45.00 55.00 65.00 75.00 85.00 95.00 100.00

Resistance Nominal Ohm 67,021 35,305 19,338 11,058 6,530 5,079 3,143 2,000 1,306 873 597 416 296 214 157 136

Resistance Minimum Ohm

Maximum Ohm

Resistance Tolerance*

Temperature Tolerance†

64,412 34,230 18,944 10,880 6,464 5,029 3,114 1,983 1,295 867 593 414 293 211 154 133

69,747 36,418 19,843 11,240 6,597 5,130 3,172 2,018 1,317 880 601 419 299 218 161 139

4.07 3.15 2.35 1.65 1.03 1.00 0.94 0.88 0.83 0.79 0.74 0.70 1.00 1.59 2.12 2.37

0.60 0.50 0.40 0.30 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.30 0.50 0.70 0.80

* in ± % † in ± °C

ELECTRICAL MOTOR CONTROLS for Integrated Systems APPLICATIONS MANUAL

Application — Photoconductive Cells Photoconductive cells are used in many applications in which it is important to know whether light is present. Such applications include headlights that automatically turn on, automatic glare reduction on rearview mirrors, and security lighting. In an automobile electrical system, a manual/auto switch is used to place the low beam headlights in an automatic or manual position. In the automatic position, a photoconductive cell automatically turns the lights on at night by returning the SSR contact to the NC position. An off/high beams on switch is used to manually turn the high beam headlights on. An adjustable resistor (R) is used to set the sensitivity that determines when the lights automatically turn on. See Automobile Electrical System.

–

12 VDC

SSR R

PHOTOCELL

SSR

AUTO

MANUAL OFF HIGH BEAMS ON 1

LIGHTING CIRCUIT TERMINAL STRIP

HEADLIGHT ELEMENTS HIGH BEAM

LOW BEAM

HIGH BEAM

LOW BEAM

HEADLIGHTS

AUTOMOBILE ELECTRICAL SYSTEM

Chapter 21 — Semiconductor Input Devices

Application — Photoconductive Diodes Photoconductive diodes (photodiodes) are used in optocoupler (optoisolator) circuits. An optocoupler is a circuit in which the input is coupled to the output by light. Optocouplers use a light emitting diode (LED) on the input and a photodiode on the output. Because the input and output are connected through a beam of light and not wires or transformers, their circuits are electrically isolated from each other preventing any transient voltages, short circuits, etc. from being transferred from one circuit to the other. Optocouplers can link one DC circuit directly to another DC circuit or the photodiode can control a transistor or SCR for switching electronic circuits or higher current DC circuits. Optocouplers can also control an AC output by using the photodiode to control a triac. See Optocouplers.

OPTOCOUPLERS PHOTODIODE

LED 1

TO DC CIRCUIT

FROM DC CIRCUIT 2

PHOTODIODE OUTPUT

PHOTODIODE

LED 3

FROM DC CIRCUIT

4 2 5

VOLTAGE SUPPLY

TO DC CIRCUIT

OUTPUT

GROUND A

NPN TRANSISTOR OUTPUT

C G

SCR FOR HIGHER DC CURRENT SWITCHING PHOTODIODE

LED

VOLTAGE SUPPLY 3

FROM DC CIRCUIT

TRIGGER CIRCUIT

OUTPUT

TRIAC

TO AC CIRCUIT

GROUND

TRIAC (AC) OUTPUT

ELECTRICAL MOTOR CONTROLS for Integrated Systems APPLICATIONS MANUAL

Application — Pressure Sensors Pressure sensors (transducers) output a signal proportional to the applied pressure. Pressure sensors that output a voltage or current are available. The standard voltage output is 0 VDC to 10 VDC. The standard current output is 4 mA to 20 mA. Current sensors can be two-wire or three-wire types. Voltage sensors can be three-wire or four-wire types. See Pressure Sensors.

PRESSURE SENSORS PRESSURESENSING ELEMENT

GREEN RED

BLACK WHITE

DEVICE

SYMBOL

PRESSURE SENSOR

STANDARD CABLE LABELING RED = VOLTAGE SUPPLY BLACK = ELECTRICAL SUPPLY VOLTAGE GROUND WHITE = POSITIVE VOLTAGE OUTPUT SIGNAL GREEN = NEGATIVE VOLTAGE OUTPUT SIGNAL

RED

–

RED

BLACK

–

TWO-WIRE SENSOR (4 mA TO 20 mA OUTPUT)

BLACK

WHITE

METER, PLC, DRIVE, ETC.

GREEN

–

RED

–

FOUR-WIRE SENSOR (0 V TO 10 V OUTPUT)

THREE-WIRE SENSOR (4 mA TO 20 mA OUTPUT)

METER, PLC, DRIVE, ETC.

–

RED

WHITE

BLACK

–

THREE-WIRE SENSOR (0 V TO 10 V OUTPUT)

Chapter 21 — Semiconductor Input Devices

Application — Flow Detection Sensors Flow detection sensors must be positioned properly in a piping system to operate correctly at all times. For proper operation, a flow detection sensor must be positioned upstream from any bends a distance equal to at least 20 times the pipe diameter. In addition, a flow detection sensor must be positioned downstream from any bends a distance equal to at least 5 times the pipe diameter. See Flow Detection Sensors.

FLOW DETECTION SENSOR

D = PIPE DIAMETER 20 D

FLOW DETECTION SENSORS

Application — Hall Effect Sensors Hall effect sensors are magnetically actuated switches. Like most switches, they are available in different packages and pin configurations. The switch output depends on whether a north or south magnetic pole is applied to the sensor. The output is either high (voltage out) or low (no voltage out). See Hall Effect Sensors. SOUTH POLE

NORTH POLE

2 1 OUT = HIGH

SOUTH POLE

2 1 OUT = LOW

1 3

OUT = HIGH

OUT = LOW

PIN 1 = SUPPLY VOLTAGE IN PIN 2 = OUTPUT PIN 3 = GROUND

ELECTRICAL MOTOR CONTROLS for Integrated Systems APPLICATIONS MANUAL

Application — Proximity Sensors A proximity sensor is an electrical switch that does not require physical contact for activation. The three types of proximity sensors are inductive, capacitive, and photoelectric sensors. Inductive sensors detect metallic objects. Nominal sensing distances range from 0.5 mm to 50 mm. The maximum sensing distance depends on the size of the object to be sensed and the type of metal. For example, iron is sensed at twice the distance of aluminum. Applications for inductive sensors include positioning, fan blade detection, drill bit breakage, and solid-state replacement of mechanical limit switches. See Inductive Sensors.

INDUCTIVE SENSORS SPECIFICATIONS SUPPLY VOLTAGE

10 VDC TO 40 VDC

AMBIENT TEMPERATURE

20 C TO +60 C

TARGET

FERROUS METALS

SENSING DISTANCE

40 mm

LEAKAGE CURRENT

1.7 mA

RESPONSE TIME

150 Hz

OUTPUT

MINIMUM: 20 mA MAXIMUM: 200 mA

SIZE (mm)

Y X

TYPE D

RED

BLACK

WHITE

BLUE

BLUE BLACK

NPN TRANSISTOR OUTPUT (CURRENT SINK)

THREADED TUBULARS

RED

PNP TRANSISTOR OUTPUT (CURRENT SOURCE)

Chapter 21 — Semiconductor Input Devices

Capacitive sensors detect conductive and nonconductive solids, fluids, or granulated substances. Nominal sensing distances range from 3 mm to 20 mm. The maximum sensing distance depends on the physical and electrical characteristics (dielectric constant) of the object to be detected. Materials with larger dielectric values are easier to detect with a capacitive sensor. Applications for capacitive sensors include sensing the level of products such as sugar, grain, and sand in a container. See Capacitive Sensors.

CAPACITIVE SENSORS SPECIFICATIONS 80 mm

SUPPLY VOLTAGE

10 VDC TO 40 VDC

AMBIENT TEMPERATURE TARGET SENSING DISTANCE

20 C TO +60 C MATERIALS W/ DIELECTRIC CONSTANT OF +1.2 10 mm

LEAKAGE CURRENT

1.7 mA

RESPONSE TIME

100 Hz

OUTPUT

MINIMUM: 20 mA MAXIMUM: 150 mA

120 mm

RED +

WHITE

20 mm

BLACK

WHITE

BLUE

BLUE BLACK

NPN TRANSISTOR OUTPUT (CURRENT SINK)

RED

PNP TRANSISTOR OUTPUT (CURRENT SOURCE)

ELECTRICAL MOTOR CONTROLS for Integrated Systems APPLICATIONS MANUAL

Photoelectric sensors detect most materials and have the greatest sensing distance. Nominal sensing distances range to over 150 cm for sensors that do not use a separate reflector or receiver. Photoelectric sensors that use a separate receiver have nominal sensing distances that range over 100′. The maximum sensing distance depends on the color and type of surface of the reflecting object. Applications using photoelectric sensors include detecting an object moving along a conveyor system and no-touch detection in which the objects to be detected are excessively hot, light, or untouchable. See Photoelectric Sensors.

PHOTOELECTRIC SENSORS SPECIFICATIONS

WIRING

WORKING RANGE

CONTACT RATING

15 A RESISTIVE

WORKING RANGE (DETECTION ZONE)

A&B

POWER SOURCE

1&3

NO CONTACT

1&4

NC CONTACT

ACTIVATING FREQUENCY 0.2 SECONDS POWER SOURCE

115 VAC

LIGHT 5&6 CONNECTED OPERATED A B

6 CABLE

1 4

DARK 5 & 6 NOT CONNECTED OPERATED

INVISIBLE INFRARED LIGHT BEAM REFLECTOR

5 6

OPERATION LIGHT-OPERATED RELAY RELEASES WHEN LIGHT BEAM IS INTERRUPTED BY AN OBJECT MOVING OUT OF BEAM.

DARK-OPERATED RELAY OPERATES WHEN LIGHT BEAM IS INTERRUPTED BY AN OBJECT MOVING IN FRONT OF BEAM.

POWER SOURCE LIGHT BEAM INTERRUPTED LIGHT OPERATED RELAY ON DARK OPERATED RELAY ON

Sensor Installation Proximity sensors have a sensing head that produces a radiated sensing field. This sensing field detects the target of the sensor. The sensing field must be kept clear of interference for proper operation. Interference is any object other than the object to be detected that is sensed by a sensor. Interference may come from objects close to the sensor or from other sensors. General clearances are required for most proximity sensors. 8

Chapter 21 — Semiconductor Input Devices

Flush-Mounted Inductive and Capacitive Proximity Sensors When flush mounting inductive and capacitive proximity sensors, a distance equal to or greater than twice the diameter of the sensors is required between sensors. If two sensors of different diameters are used, the diameter of the largest sensor is used for installation. See Flush Mounted Sensors. For example, if two 8 mm inductive proximity sensors are flush mounted, at least 16 mm is required between the sensors. DISTANCE IS EQUAL TO OR GREATER THAN TWO TIMES DIAMETER OF SENSOR

16 mm

d 8 mm

FLUSH MOUNTED SENSORS

Non-Flush Mounted Inductive and Capacitive Proximity Sensors When non-flush mounting inductive and capacitive proximity sensors, a distance of three times the diameter of the sensor is required within or next to a material that can be detected. Three times the diameter of the largest sensor is required when inductive and capacitive proximity sensors are installed next to each other. Spacing is measured from center to center of the sensors. When inductive and capacitive proximity sensors are mounted opposite each other, six times the rated sensing distance is required for proper operation. See Non-Flush Mounted Sensors. For example, if two 16 mm capacitive proximity sensors are non-flush mounted, at least 48 mm is required between the sensors. DISTANCE IS THREE TIMES DIAMETER OF SENSOR 48 mm 48 mm

d 16 mm

ELECTRICAL MOTOR CONTROLS for Integrated Systems APPLICATIONS MANUAL

Mounting Photoelectric Sensors Photoelectric sensors transmit a beam of light. The beam of light detects the presence or absence of an object. Only part of the light beam is effective when detecting the object. The effective light beam is the area of light that travels directly from the transmitter to the receiver. If the object does not completely block the effective light beam, the object is not detected. The body of a photoelectric sensor may be cylindrical, rectangular, or slotted. When mounting photoelectric sensors, the receiver is positioned to receive as much light as possible from the transmitter. Because more light is available at the receiver, greater operating distances are allowed and more power is available for the system to see through dirt in the air, on the transmitter, and on the receiver lens. The transmitter is mounted on the clean side of the detection zone because light scattered by dirt on the receiver lens affects the system less than light scattered by dirt on the transmitter lens. See Photoelectric Sensor Positioning.

PHOTOELECTRIC SENSOR POSITIONING RECEIVER

RECEIVER DIRT CREATES SCATTERING CLOSE TO RECEIVER

FIELD OF VIEW

TRANSMITTER

FIELD OF VIEW

EFFECTIVE BEAM

DIRTY ENVIRONMENT

DIRECT SCAN

CORRECT

RECEIVER

RETROREFLECTOR

TRANSMITTER EFFECTIVE BEAM

FIELD OF VIEW

RETROREFLECTIVE SCAN

DIRTY ENVIRONMENT

INCORRECT

Chapter 21 — Semiconductor Input Devices

Frequency Activating frequency is the limit to the number of pulses per second that can be detected by a photoelectric control in a time period. All photoelectric controls have an activating frequency. To determine the required activating frequency of a photoelectric application, the following procedure is used: 1. Determine the maximum speed of the objects to be detected. The speed of the objects is found by measuring the speed of the objects (in ft/min or in./sec) and converting the speed to sec/in. See Speed Conversions. For example, cartons on a conveyor travel at 21 ft/min. Twenty-one feet per minute equals 0.238 sec/in. (from Speed Conversions table).

SPEED CONVERSIONS Ft/min

In./min

Ft/sec

In./sec

Sec/in.

0.017

0.2

0.050

0.6

1.666

0.083

1.0

1.000

0.116

1.4

0.714

108

0.150

1.8

0.555

132

0.183

2.2

0.435

156

0.216

2.6

0.385

180

0.249

3.0

0.333

204

0.282

3.4

0.294

228

0.315

3.8

0.263

252

0.349

4.2

0.238

276

0.382

4.6

0.2172

300

0.415

0.200

480

0.664

0.125

720

0.996

0.0833

960

1.328

0.0625

100

1200

1.66

0.050

200

2400

3.32

0.025

250

3000

4.15

0.020

300

3600

4.98

0.016

400

4800

6.64

0.012

500

6000

8.30

100

0.010

700

8400

11.62

140

0.007

1250

15,000

20.75

250

0.004

2500

30,000

45.5

500

0.002

2. Determine the dark input signal duration. Dark input signal duration is the time period when a photoelectric sensor is dark because the detected object is blocking the light beam. Dark input signal duration is found by multiplying the minimum dimension of the object to be detected (in in.) by the sec/in. value. For example, if a 6″ × 3″ container has a 0.263 sec/in. value, the dark input signal duration is 0.789 sec (3 × 0.263 = 0.789). © 2014 American Technical Publishers, Inc. All rights reserved

ELECTRICAL MOTOR CONTROLS for Integrated Systems APPLICATIONS MANUAL

3. Determine the light input signal duration. Light input signal duration is the time period when a photoelectric sensor is lit because no detectable object is in the light beam. Light input signal duration is found by multiplying the minimum distance between the objects to be detected by the sec/in. value. For example, if the moving objects are spaced between 4″ and 15″ on a conveyor traveling at 0.200 sec/in., the light input signal duration is 0.8 sec (4 × 0.200 = 0.8). 4. Determine activating frequency. Activating frequency of a photoelectric control application is found by adding the dark input signal duration to the light input signal duration. This value is compared to the manufacturer stated value. The activating frequency of a photoelectric control must be less than the activating frequency required for the application.

Application — Ultrasonic Sensors Ultrasonic sensors are used to detect an object that is close (inches) or far (feet). Ultrasonic sensors are available for different width and distance detection ranges. See Ultrasonic Sensors. SILO INTAKE PIPE

STORAGE SILO 30 FEET

BULK RAILCAR VACUUM E PRESSUR UNLOADER

D – 20 FEET

– 15 FEET SENSOR TYPE

DISTANCE – 10 FEET

– 5 FEET

– 0 FEET WIDTH

RATED RANGE PROBABLE RANGE (BASED ON OBJECT TO BE DETECTED)

ULTRASONIC SENSORS 12

Name_______________________________________________ Date________________________

Activity — Thermistors Draw the graph showing the characteristics of the thermistor from the Temperature vs. Resistance—2000 Ω NTC Thermistor chart on page 1.

RESISTANCE (Ω)

0.75 R

0.5 R

0.25 R

–40

–30

–20

–10

100

TEMPERATURE (°C)

ELECTRICAL MOTOR CONTROLS for Integrated Systems APPLICATIONS MANUAL

Activity — Photoconductive Cells Complete the following steps and answer the questions using the Automobile Electrical System. +

– 12 VDC

DMM 1

DMM 2

DMM 3

SSR R

PHOTOCELL

SSR

AUTO

MANUAL OFF HIGH BEAMS ON 1

LIGHTING CIRCUIT TERMINAL STRIP

HEADLIGHT ELEMENTS HIGH BEAM

LOW BEAM

HIGH BEAM

LOW BEAM

HEADLIGHTS

AUTOMOBILE ELECTRICAL SYSTEM

1. Connect DMM 1 to measure the incoming power from the battery/charging circuit. �� 2. DMM 1 reads ___ if the circuit is working properly. 3. Connect DMM 2 to measure the voltage out of the auto switch and into the SSR contact to determine whether voltage is present at that point. �� 4. DMM 2 reads ___ if the circuit is working properly, the switch is in the auto position, and it is dark outside. �� 5. DMM 2 reads ___ if the circuit is working properly and the switch is in the manual position. 6. Connect DMM 3 to measure the voltage at the low beam headlights. �� 7. Can there be a voltage reading at both terminal 2 and 4 at the same time? 14

Chapter 21 — Semiconductor Input Devices

Activity — Photoconductive Diodes In the following application, a DC to DC optocoupler is used to isolate a 5 VDC control circuit from a 24 VDC motor starter coil and a 90 VDC power circuit. 1. Connect the control circuit so that the three-position selector switch and the pressure switch control the DC motor. In the hand position the motor is on. In the off position the motor is always off. In the auto position the motor is on any time the pressure switch is closed. Resistor (R) is used as a current limiting resistor (load) in the control circuit. The resistor is connected between the negative DC power supply and the photodiode.

90 V DC POWER SOURCE L1

5 VDC

24 VDC HAND

OFF AUTO

24 VDC DC MOTOR STARTER COIL

2 RESET

90 VDC RATED SHUNT MOTOR

ELECTRICAL MOTOR CONTROLS for Integrated Systems APPLICATIONS MANUAL

Activity — Pressure Sensors A DMM can be used to test pressure sensor operation. For each DMM, test the pressure sensor operation by drawing in the selector switch position and connecting the leads to the meter and into the circuit (sensor and power supply).

BLACK LEAD

RED LEAD

BLACK RED 0 VDC to 10 VDC WHITE PRESSURE SENSOR (TRANSDUCER)

–

RED

–

BLACK 0 VDC to 10 VDC GREEN WHITE PRESSURE SENSOR (TRANSDUCER)

Chapter 21 — Semiconductor Input Devices

BLACK LEAD

RED LEAD

–

RED

–

BLACK

4 mA to 20 mA

BLACK

WHITE PRESSURE SENSOR (TRANSDUCER)

PRESSURE SENSOR (TRANSDUCER)

Activity — Flow Detection Sensors 1. Complete the table by determining the minimum distance in inches for each pipe size.

Pipe Diameter

¹⁄₂″ ³⁄₄″ 1″ 2″

ELECTRICAL MOTOR CONTROLS for Integrated Systems APPLICATIONS MANUAL

Activity — Hall Effect Sensors Connect the Hall effect sensor, SSR, and power supply so the AC load is controlled by a magnetic field applied and removed from the Hall effect sensor.

LINEAR OUTPUT HALL EFFECT SENSOR NOTCHED TUBE

CORK FLOATER

FLOAT TANK

MAGNET

LIQUID LEVEL

DIGITAL OUTPUT HALL EFFECT SENSOR

MAGNET

HALL EFFECT SENSOR

SSR (–)

(+) 1

C LO

TO AC C RC T L

IN = 3 VDC TO 32 VDC OUT = 24 VAC TO 120 VAC

24 V

C O N T R O L

POWER SUPPLY

Chapter 21 — Semiconductor Input Devices

Activity — Proximity Sensors In the bottling application, a capacitive proximity sensor is used to detect bottle flow along the system. Identify the color of each wire of the proximity sensor using the Capacitive Sensors chart on page 7.

PROXIMITY SENSORS

CONVEYOR 1

WIRE 1

0123 BOTTLE COUNTER

WIRE 2 CAPACITIVE SENSOR DETECTING BOTTLES

WIRE 3

CONVEYOR 2

CONVEYOR 3

WAREHOUSE CONVEYOR

ELECTRICAL MOTOR CONTROLS for Integrated Systems APPLICATIONS MANUAL

In the bottling application, a photoelectric sensor is used to detect cartons moving along the system. Identify the number/letter of each wire of the photoelectric sensor using the Photoelectric Sensors chart on page 8. WIRE 1 L1

L2 PE

WIRE 2

0123 WIRE 4

CARTON COUNTER

WIRE 3

�� 4. Wire 1 number/letter is ___. �� 5. Wire 2 number/letter is ___. �� 6. Wire 3 number/letter is ___. �� 7. Wire 4 number/letter is ___. Determine the minimum distance required between the sensors for proper operation. �� 8. The minimum distance required between the sensors for proper operation is ___ mm.

6 mm

�� 9. The minimum distance required between the sensor and the surrounding material for proper operation is ___ mm.

12 mm

Chapter 21 — Semiconductor Input Devices

�� 10. The minimum distance required between the sensors and the surrounding material for proper operation is ___ mm. (60)

20 mm

Answer the questions using the Speed Conversions chart on page 11. A photoelectric sensor detects 2″ × 2″ objects that are 5′ apart and travel at 60′/min. �� 11. The dark input signal duration is ___ sec. �� 12. The light input signal duration is ___ sec. �� 13. The activating frequency of the application is ___ sec. A photoelectric sensor detects 0.5″ square objects that are 2″ apart and travel at 200′/min. �� 14. The dark input signal duration is ___ sec. �� 15. The light input signal duration is ___ sec. �� 16. The activating frequency of the application is ___ sec. A photoelectric sensor detects 2″ square objects that are 3″ apart and travel at 1250′/min. �� 17. The dark input signal duration is ___ sec. �� 18. The light input signal duration is ___ sec. �� 19. The activating frequency of the application is ___ sec. A photoelectric sensor detects 0.25″ × 0.25″ objects that are 0.25″ apart and travel at 15′/min. �� 20. The dark input signal duration is ___ sec. �� 21. The light input signal duration is ___ sec. �� 22. The activating frequency of the application is ___ sec.

ELECTRICAL MOTOR CONTROLS for Integrated Systems APPLICATIONS MANUAL

Activity — Ultrasonic Sensors Answer the following questions using the sensor rated range, probable range, and sensor output data.

ULTRASONIC SENSORS D – 20 FEET

– 15 FEET SENSOR TYPE

DISTANCE – 10 FEET

– 5 FEET

– 0 FEET WIDTH

SENSOR RATED RANGE SENSOR PROBABLE RANGE (BASED ON OBJECT TO BE DETECTED)

Analog Voltage (VDC)

Analog Current (mA)

RATED DISTANCE

RATED RANGE

Current Output Type

RATED DISTANCE

RATED RANGE

Voltage Output Type

SENSOR OUTPUT

�� 1. The rated width range for sensor type A at half the rated distance range is ___ ft. �� 2. The probable distance range for sensor type B is ___ ft. �� 3. The rated width range for sensor type C at half the rated distance range is ___ ft. �� 4. The probable distance range for sensor type C is ___ ft. �� 5. If ultrasonic sensor type D is used to detect product in a 30′ silo and is mounted at the top of the silo, the distance at which the sensor is rated to detect a rising product (height of product from bottom of silo) is ___ ft. �� 6. A voltage output type sensor outputs ___ VDC at half of its rated range. 22