GWIEC / PRODUCT SELECTION GUIDE
Compare sensor housings and related series, then check sensing distance, mounting and wiring in the technical guide.
Technical guide ↓Working principles, technical terms, installation, electrical connections, precautions, applications and model-code interpretation from catalog pages 01–08.
Proximity switches, also called proximity sensors, include inductive, capacitive, analog, Hall-effect and magnetic types. They can be used with PLCs, microcontrollers, logic circuits, electronic counters, solid-state relays and small relays.
An inductive proximity sensor contains a high-frequency oscillator, detector, amplifier, trigger and output circuit. The oscillator creates an alternating electromagnetic field at the sensing face. As a metal target approaches, eddy currents in the metal absorb oscillator energy and reduce or stop oscillation. The oscillating and non-oscillating states are converted into a binary switching signal, amplified and delivered by the output stage.
A capacitive proximity sensor contains a high-frequency oscillator and amplifier. The sensing face and earth form part of a capacitor in the oscillating circuit. The circuit initially remains in a non-oscillating state. When a target approaches, its capacitance changes and the oscillator starts. These two states are converted into a binary switching signal through the amplifier.
An analog sensor, also called a linear displacement sensor, produces an electrical output that changes in a linear relationship with the distance of a metal target from its sensing face. This signal can be used for monitoring.
A Hall-effect proximity sensor contains a Hall integrated circuit. The Hall effect converts the presence or absence of a magnetic field into a switching signal. Applications include signal detection and automatic control.
A magnetic sensor contains a reed switch and an amplifier. An approaching external magnetic field magnetizes and operates the reeds. The amplifier increases the switching capability to control an external circuit.
Operating distance is a principal proximity-switch parameter. It mainly depends on the sensing-face diameter; target material and ambient temperature also affect it. For magnetic and Hall-effect sensors, an iron mounting plate and magnetic-field strength can also affect operating distance. Targets may approach axially or radially; axial approach is generally used.
A standard nominal value that does not include external environmental influences.
A smooth ST37 steel square, 1 mm thick, with a side length of 3 × Sn. Changes in target dimensions or material reduce the sensing range relative to this reference.
The distance measured at rated supply voltage and room temperature of 23 ±5 °C: 0.9 Sn ≤ Sr ≤ 1.1 Sn.
The distance measured over the permitted ambient-temperature range of -25 to +70 °C and from 85% to 110% of rated input voltage: 0.9 Sr ≤ Su ≤ 1.1 Sr.
Within this range, operation with the measuring target is reliable: 0 ≤ Sa ≤ 0.81 Sn.
The variation in effective operating distance measured over 8 hours at an ambient temperature of 23 ±5 °C, with uncontrolled relative humidity and a supply of Ue ±5 as printed in the catalog: R ≤ 0.1 Sn. The source does not state a unit after the ±5 supply tolerance; confirm the applicable specification.
The catalog describes the switch as disconnected when the separation between the target and sensing face is greater than the rated operating distance. The original distance diagram below distinguishes the sensing-distance bands and hysteresis.
The attenuation coefficient expresses the reduction in operating distance for a material relative to the ST37 steel reference target. For inductive switches, target conductivity is an important influence.
| Material | Attenuation coefficient |
|---|---|
| Steel | 1.0 |
| Stainless steel | 0.85 |
| Aluminum | 0.4 |
| Brass | 0.4 |
| Copper | 0.3 |
| Material | Attenuation coefficient |
|---|---|
| Steel | 1.0 |
| Stainless steel | 1.0 |
| Aluminum | 0.75 |
| Brass | 0.6 |
| Copper | 0.45 |
Current consumed by the proximity switch when no load is connected.
The maximum load current during continuous operation.
The current permitted for a short interval while the switch is closed without damaging the switch.
Current flowing through the load while the switch is in its off state.
The minimum-to-maximum supply-voltage range within which the switch operates as specified.
The voltage measured across the switch when it is turned on.
The maximum switching rate between attenuated and non-attenuated states, expressed in hertz (Hz).
A non-flush, unshielded sensor can obtain a larger operating distance, related to its diameter. To prevent surrounding metal from influencing operation, maintain clearance around the sensing head as shown in Figure 1.
Internal shielding reduces the lateral magnetic field of a flush sensor. The catalog gives an approximate sensing distance of 60% of the corresponding unshielded type and shows the sensor installed flush in metal in Figure 2. Magnetic sensors are described as unaffected by the mounting condition provided the surrounding material is not magnetized.
Figure 3 shows parallel-installation spacing to reduce mutual interference. The cylindrical examples indicate F = 3D for non-flush sensors and F = 1D for flush sensors. Refer to the instructions for the exact model and mounting conditions.
Maintain the clearances indicated by A, B, C, D and E. The measuring board represents the detection target. Refer to the model-specific operating instructions for dimensions.
Maintain the illustrated minimum separation to avoid mutual interference. F and G identify spacing in the original drawing; model-specific instructions provide the corresponding values.
The catalog illustrates a DC three-wire NPN output connected to a programmable-controller DC input module.
Connect the sensor in series with the load. Do not connect a two-wire sensor directly across the power supply. The catalog describes polarity protection, a small leakage current in the open state and a voltage drop across the switching element in the closed state.
The load and supply are connected separately. The catalog describes reverse-polarity, short-circuit and overload protection, with residual current small enough to neglect in this description.
The sensor provides two output states: normally open and normally closed. Keep the wire colors and terminal assignments shown in the selected circuit.
Connect the sensor in series with its load, never directly across the supply. A small leakage current remains in the open state; the switching element has a small voltage drop when closed.
Diagram legend: BN = brown; BK = black; WH = white; BU = blue; RD = red; GY = gray. NO = normally open; NC = normally closed. The original drawings retain their terminal numbers, Chinese labels and bilingual switching-state annotations; the English captions identify each circuit.
Any one active sensor can drive the load. The permissible number of parallel sensors depends on the sum of their leakage currents and whether that current affects load operation. Do not mix NPN and PNP types in this OR connection. The Chinese source states this restriction; the printed English sentence says the opposite.
The load is driven only when all connected sensors operate. The permissible number of sensors depends on the sum of their saturation-voltage drops and the supply voltage remaining available to each sensor. The catalog describes the response as including the accumulated initialization/reset delays of the connected sensors.
The source separately illustrates an AND series circuit using NPN and PNP outputs. Follow the specific illustrated arrangement and the exact model instructions; the OR restriction above must not be reversed by the catalog’s English wording.
When the switch is connected to a counter or PLC with an internal initialization/reset circuit, the source describes no normal initialization problem. Avoid the following conditions: a target close to the switching distance during power-on or power-off; a sharp rise or fall in the circuit time constant for DC voltage-output or DC switching types; or oscillation and noise when current is made or broken in an AC switching type.
Do not directly connect a load with a large inrush current, such as a capacitor or lamp. Use the relay connection or a series current-limiting resistor described in the source. Choose the current limit within the sensor’s load-current rating and connect it through the load.
The original expressions relate supply voltage, permitted peak-load current, limiting resistance R and allowable resistor power. The figure prints resistance in kΩ; verify consistent units and the exact model ratings before selecting components.
Do not use the switch exposed outdoors without protection; fit a protective cover where necessary.
Do not strike the sensing face with hard objects. Use a protective cover where required.
Do not use the sensor in an environment containing corrosive substances.
Do not tighten with excessive force. Use a spring washer when fastening as illustrated.
Route sensor wiring in its own metal flexible conduit. Do not put it in the same conduit as power or motor wiring.
Do not pull the proximity-switch cable with excessive force.
Inductive sensors are used in aviation, aerospace and industrial production. The source describes their use for conductive targets, or targets fixed to a metal object, where their switching response, interference resistance, application range and cost suit the task.
1. Code
2. Type
3. Shape
| 4. Sensing distance
5. Category
| 6. Shape size
7. Output form
8. Output state
| 9. Non-standard voltage
Temperature codes
| 10. Connector
|
1. Code
2. Type
| 3. Shape
4. Shape size
| 5. Detecting distance
6. Detecting type
| 7. Output form
8. Output state
| 9. Connector
|
The source uses distance code 10 for both 10 cm and 10 m. Confirm the complete model rather than interpreting that code by itself. Category codes, including S, identify the source’s ordering scheme and do not establish certification for a selected model. The brand field in both code schemes is G: GWIEC.
The source presents this family for corresponding cylindrical applications. Select a replacement using the exact model specifications.
Reverse-polarity and short-circuit protection; direct PLC connection as specified.
For common operating locations, with medium environmental resistance as described in the source.
Red LED operating-state indication.
Economical and simple operation.
Applications include the functions of small switches and limit switches.
IP67 enclosure protection in the source description.
Read the precautions in the operating instructions before use.
The source identifies corresponding types from Omron and Autonics; verify the complete model and electrical/mechanical compatibility.
Reverse-polarity and short-circuit protection; direct PLC connection as specified.
Long service life, high reliability and strong environmental resistance.
Reinforced housing.
IP67 enclosure protection in the source description.
Read the operating precautions before use.
The source identifies corresponding types from Pepperl+Fuchs and TURCK; compatibility requires model-specific confirmation.
Reverse-polarity and short-circuit protection; direct PLC connection as specified.
Current overload protection and imported IC components as described in the source.
Long service life, high reliability and strong environmental resistance.
Red LED operating-state indication.
Full-thread body provides installation adjustment and permits wrench/clamp mounting.
Reinforced housing and cable strain protection.
IP67 enclosure protection in the source description.
Read the operating precautions before use.
Reverse-polarity and short-circuit protection; direct PLC connection as specified.
Economical and simple operation.
Long service life, high reliability and strong environmental resistance.
Red LED operating-state indication.
IP67 enclosure protection in the source description.
Read the operating precautions before use.
| Item | Catalog description |
|---|---|
| Hysteresis | 10% or more of the detecting distance in the Chinese source; the printed English says 10% below. Confirm the selected model’s value. |
| Detection target | Magnetic metal. Sensing distance decreases for non-magnetic metal. |
| Supply voltage | DC type: 12–24 V DC (6–36 V), with peak-to-peak ripple below 10%. AC type: 110–220 V AC (36–250 V), 50/60 Hz. |
| Current consumption | N/P types: below 13 mA; D type: below 0.8 mA; A type: below 1.7 mA. |
| Control output | N/P types: below 300 mA; D type: below 200 mA; A type: below 400 mA. |
| Circuit protection | N/P/D types: reverse-connection protection, surge absorption and load short-circuit protection. A type: surge absorption. |
| Ambient temperature and humidity | Operation/storage: -30 to +65 °C, without freezing or condensation; relative humidity 35–95%. |
| Insulation resistance | At least 50 MΩ between live parts and the housing, using a 500 V DC megohmmeter. |
| Dielectric withstand | 1000 V AC, 50/60 Hz, 1 minute, between live parts and the housing. |
| Temperature influence | Relative to +23 °C: within ±15% of detecting distance over -30 to +65 °C; within ±10% over -25 to +60 °C. |
| Supply-voltage influence | Within ±10% of detecting distance for a rated-supply variation of ±15%. |
| Enclosure | IP67 (source reference to IEC enclosure classification). |
| Materials | Housing: nickel-plated brass. Sensing face: ABS. |
These are the chapter’s general descriptions. The exact model table and operating instructions determine the applicable voltage, current, temperature, mounting and protection requirements.
Large-head sensors
Smooth cylindrical
Threaded cylindrical
Panel-mount cylindrical
Miniature cylindrical
Rectangular sensors
