LJ12A3-4-Z/BY proximity sensor with coiled cable, three leads, two mounting nuts and two lock washers

LJ12A3-4-Z/BY Inductive Proximity Sensor - PNP NO, 4 mm

$5.99 NZD
Save 6% at 3+
Skip to product information
LJ12A3-4-Z/BY proximity sensor with coiled cable, three leads, two mounting nuts and two lock washers
  • LJ12A3-4-Z/BY proximity sensor with coiled cable, three leads, two mounting nuts and two lock washers
  • Close view of the blue sensing face, threaded body and fitted mounting nuts on the LJ12A3-4-Z/BY sensor
  • LJ12A3-4-Z/BY sensor with mounting nuts and washers fitted, showing the full body and cable exit
  • LJ12A3-4-Z/BY sensor with 56.7 mm body-length annotation and M12 thread callout
LJ12A3-4-Z/BY Inductive Proximity Sensor - PNP NO, 4 mm
SKU: SEN-LJ12A3-PNP-NO

LJ12A3-4-Z/BY Inductive Proximity Sensor - PNP NO, 4 mm

$5.99 NZD
Dispatch: Within 24 hours 7-day dispatch, excluding public holidays

NZ Post: 1-2 days urban · 2-4 days rural

Shipping from $5.99 urban / $9.99 rural.

Buy more, pay less Prices shown are per unit. Add enough of this item and the lower rate applies on its own at checkout. There is no code to enter and you do not need to buy a pack. Choosing a tier here just sets the quantity for you. Larger quantities go out in the same bag, so packing, handling and postage cost us less per unit. We pass that saving straight on to you, so you can buy more for less.

Easy 30-day returns · 12-month warranty

Free Urban delivery on orders over $66
Urban $66 Rural $88

The LJ12A3-4-Z/BY is an M12 inductive proximity sensor for detecting metal without contact. Its PNP normally-open output switches on when a suitable metal target enters the nominal 4 mm sensing range. Use it for position sensing and end-stop detection with a compatible DC control input.

Specifications

ModelLJ12A3-4-Z/BY
OutputPNP, normally open, three-wire
Supply6 to 36 V DC; nominal 12 to 24 V
Nominal sensing distance4 mm ±10% with iron target
Recommended set distance0 to 3.6 mm
Maximum output current300 mA
Response frequency500 Hz
MountingM12 threaded barrel, non-flush
Body length56.7 mm nominal, excluding cable relief
Housing / sensing faceNickel-plated brass / ABS
Enclosure ratingIP67; protect cable joints separately
Temperature-30 to +65 °C, no condensation or freezing

Datasheets

Full technical datasheetPDF

What's in the box

1×
LJ12A3-4-Z/BY sensor with attached cable

Includes two mounting nuts and two lock washers.

Great for

Metal part detection
Position sensing on jigs
CNC end stops with a compatible PNP input

Wiring & getting started

  1. Check the input and wiring

    Confirm the diagram on the supplied sensor. Standard three-wire PNP wiring is brown to positive, blue to 0 V and black to the compatible input or load, with its return at 0 V.

  2. Mount and power it

    Keep the blue sensing face proud of surrounding metal. With power off, connect a regulated DC supply within the stated range. Apply power and bring an iron target within the set distance.

  3. Check detection

    The input should activate near the target and release when it is removed. Allow for a shorter detection range with non-magnetic metals.

Note: The PNP output can approach the sensor supply voltage. Use a suitable interface for 3.3 V or 5 V logic; do not connect the output directly to a microcontroller GPIO. Replacing an NPN sensor requires checking the controller input and wiring.

Frequently Asked Questions

Answers to the questions buyers ask most.

Is this sensor PNP or NPN?
The LJ12A3-4-Z/BY is PNP normally open. Its output sources current when metal is detected. Check controller compatibility when replacing an NPN sensor.
Can I connect it directly to an Arduino or ESP32?
Use a suitable interface. The sensor needs 6 to 36 V DC, and its output can approach the supply voltage. Do not connect the black output wire directly to a 3.3 V or 5 V GPIO.
Does it detect aluminium or plastic?
It detects metal. Non-magnetic metals such as aluminium generally have a shorter range than iron. It does not detect plastic or wood.
What is included?
One sensor with its attached cable, two mounting nuts and two lock washers.

Have a Question About This Product?

Send it through and we will get back to you by email.

Why Buy from NZN

Useful parts, fair prices and someone local to help.

I'm Lukas, an engineering student and maker based in Te Awamutu. NZN grew out of a CNC build that dragged on for months because every missing cable, bolt or electronic part meant another overseas order. I started the shop so Kiwi makers can spend more time building and less time waiting for the next parcel.

More about NZN Electronics

  • Stocked here in New Zealand

    Orders are picked and packed in Te Awamutu and dispatched within 24 hours every day, excluding public holidays. NZ Post target delivery is 1-2 days urban and 2-4 days rural.

  • Fair prices, clearly shown

    Prices are kept competitive and quantity discounts are shown upfront. Free delivery starts at $66 for urban addresses and $88 for rural addresses.

  • 30-day returns and 12-month warranty

    Get in touch if something is not right and we will help sort it.

  • Practical product support

    Ask a product question and get help from a real person in New Zealand who knows the range.

You may also like