H-M Series M12/M18 Through-beam Photoelectric Sensor

Name: H-M Series M12/M18 Through-beam Photoelectric Sensor
Brand: DAIDISIKE
SKU: h-m-series-m12-m18-through-beam-photoelectric-sensor
Availability: InStock

M12/M18 through-beam sensor pairs for color-independent presence detection when the target sufficiently interrupts the beam, with 2 m to 15 m range options.

H-M Series M12/M18 Through-beam Photoelectric Sensor - product photo

🔍 Click to enlarge · 1/10

Technical Specifications

Models	H122M, H125M, H1805M, H1815M, each in N1/P1/N2/P2 output variants (16 models total)
Output type	N1 = NPN N.O.; P1 = PNP N.O.; N2 = NPN N.O.+N.C.; P2 = PNP N.O.+N.C.
Sensing mode	Through-beam (opposed mode)
Sensing range	H122M: 2 m +/-10%; H125M: 5 m +/-10%; H1805M: 5 m +/-10%; H1815M: 15 m +/-10%
Thread / barrel size	M12x63 / M18x73
Housing material	Nickel-plated brass
Supply voltage	10-30VDC

Overview

This is a through-beam (opposed-mode) photoelectric sensor set: a separate emitter and receiver are installed facing each other, and the receiver switches its output when the light beam between them is interrupted by an object. Because detection depends on beam interruption -- not on the target's reflectivity -- it suits engineers and machine builders who need dependable presence/absence detection on conveyors, chutes, gates, or passageways, especially where target color or surface (dark rubber, glossy metal, opaque film, or another target that sufficiently attenuates the beam) would confuse a diffuse or retroreflective sensor.

The H-M series covers four sensing-range classes across two barrel sizes: H122M (M12, 2 m +/-10%), H125M (M12, 5 m +/-10%), H1805M (M18, 5 m +/-10%), and H1815M (M18, 15 m +/-10%). Each range class is offered in NPN or PNP output, with either a single normally-open (N.O.) signal or complementary normally-open plus normally-closed (N.O.+N.C.) signals, for 16 models in total, all running on a 10-30 VDC supply.

How the H-M Through-Beam Sensor Pair Works

The emitter sends a continuous optical beam across the detection zone to the receiver. With the path clear, the receiver sees the emitter; when a target blocks the path, the receiver changes its output state. That opposed layout is why the H-M through-beam photoelectric sensor is much less dependent on the target's colour or gloss than a sensor that must read reflected light.

The trade-off is mechanical: both sides need mounting and power/cabling, and the two M12 or M18 barrels must share the same optical axis. Choose the range class from the real installed span, then allow alignment margin rather than specifying exactly at the published maximum.

H-M M12 M18 through-beam photoelectric sensor pair detecting a conveyor object by beam interruption — Emitter and receiver face each other; beam interruption—not target reflectivity—changes the output.

H122M, H125M, H1805M or H1815M?

Range class	Barrel	Published sensing range	Start here when
H122M	M12 × 63 mm	2 m ±10%	the span is short and the mounting hole is M12
H125M	M12 × 63 mm	5 m ±10%	a compact M12 pair must cover a wider conveyor
H1805M	M18 × 73 mm	5 m ±10%	the installation uses an M18 barrel
H1815M	M18 × 73 mm	15 m ±10%	a gate, portal or long conveyor needs the longest H-M class

After the range/body choice, select N1 or P1 for a single normally-open output, or N2/P2 for complementary normally-open plus normally-closed outputs. For other sensing principles and housings, return to the photoelectric sensor range.

Key Facts — H-M at a glance

The H1815M through-beam sensor pair reaches a sensing range of up to 15 m +/-10% from a single M18 emitter/receiver pair.
The H-M series through-beam sensors are available in four sensing-range classes: 2 m, 5 m (M12), 5 m and 15 m (M18), each with +/-10% tolerance.
N2 and P2 output versions provide complementary normally-open (N.O.) and normally-closed (N.C.) signals from a single receiver.
The M12 barrel measures M12x63 mm and the M18 barrel measures M18x73 mm, both machined from nickel-plated brass.
All 16 models in the series operate on a 10-30 VDC supply.
Through-beam (opposed-mode) sensing detects an object by beam interruption rather than returned reflectivity, making detection largely independent of color, gloss, or surface finish provided the target sufficiently interrupts the beam.

Features & Benefits

Detection independent of target color, gloss or surface finish

Because the receiver registers whether the beam is sufficiently interrupted, dark or reflective targets do not depend on returning a particular amount of light. Transparent film and glass still require testing because they may not attenuate the beam enough to switch reliably.

Up to 15 m sensing range from a compact M18 barrel pair

The H1815M variants reach 15 m +/-10%, letting one emitter/receiver pair span an entire gate, portal, or wide conveyor without intermediate supports.

Four sensing-range classes across two barrel sizes (M12/M18)

H122M (M12, 2 m +/-10%), H125M (M12, 5 m +/-10%), H1805M (M18, 5 m +/-10%), H1815M (M18, 15 m +/-10%) let you match sensor size and range to the installation without over- or under-specifying.

Complementary N.O. + N.C. outputs on N2/P2 versions

A single receiver can output both a normally-open and a normally-closed signal simultaneously, supporting positive-logic control and negative-logic alarm/interlock from one sensor.

NPN and PNP output selectable per model

N1/N2 give NPN (sinking) output, P1/P2 give PNP (sourcing) output, matching either sinking- or sourcing-input PLC/controller architectures without extra interface hardware.

Rugged nickel-plated brass barrel in standard M12/M18 threads

The metal housing (M12x63 mm / M18x73 mm) resists mechanical knocks and mounts with standard threaded nuts, compatible with common proximity/photoelectric sensor bracket systems, and holds beam alignment once locked in place.

10-30 VDC wide supply range

Runs directly off common 24 VDC industrial control power without a separate regulated supply, and tolerates typical supply fluctuation across the 10-30 VDC window.

Applications

Conveyor cross-belt object/jam detection — Through-beam sensing is unaffected by target color or gloss, making it suitable for conveyor lines carrying dark, reflective, or mixed materials.

Warehouse or workshop door / passage pass-through detection — Long-range M18 models can cover an entire door or passage span with a single emitter/receiver pair for general-purpose trigger signals (non-safety function).

Drop-point / chute material flow monitoring — Mount the beam across a chute or drop point to detect the presence or absence of material passing through.

High-transparency workpiece edge detection (film, glass edge) — An edge that sufficiently attenuates the beam can trigger detection; transparent film and glass must be tested with the actual material because some targets may transmit too much light for reliable switching.

Wide-span gate or portal presence detection — The H1815M's 15 m +/-10% range covers a wide gate or portal span, reducing the need for intermediate mounting supports.

Machine-in/out or pallet presence check in automated lines — The complementary N.O.+N.C. outputs on N2/P2 versions let one sensor feed both a control-logic input and an alarm/interlock circuit at the same time.

Retrofit/replacement in existing M12/M18 sensor footprints — Standard M12x63 / M18x73 threaded barrels fit common existing mounting holes for through-beam sensor replacement.

Models & Ordering Information

H122M -- M12 through-beam, 2 m +/-10%

H122MN1H122MP1H122MN2H122MP2

H125M -- M12 through-beam, 5 m +/-10%

H125MN1H125MP1H125MN2H125MP2

H1805M -- M18 through-beam, 5 m +/-10%

H1805MN1H1805MP1H1805MN2H1805MP2

H1815M -- M18 through-beam, 15 m +/-10%

H1815MN1H1815MP1H1815MN2H1815MP2

Suffix key: N1 = NPN, N.O. only; P1 = PNP, N.O. only; N2 = NPN, N.O.+N.C.; P2 = PNP, N.O.+N.C.

How to Select

Need <=2 m sensing range with a compact footprint: choose H122M (M12, 2 m +/-10%).
Need <=5 m range on an M12 mounting hole: choose H125M (M12, 5 m +/-10%).
Need <=5 m range but prefer the larger M18 barrel: choose H1805M (M18, 5 m +/-10%).
Need up to 15 m span, such as a gate or wide conveyor: choose H1815M (M18, 15 m +/-10%).
Match the barrel size to your existing mounting holes: M12x63 for H122M/H125M, M18x73 for H1805M/H1815M.
Match the output type to your controller's input architecture: NPN (sinking) input uses N1 or N2; PNP (sourcing) input uses P1 or P2.
Choose N1 or P1 for a single normally-open output; choose N2 or P2 when you need simultaneous normally-open and normally-closed outputs for combined control and alarm/interlock circuits.
All models share a common 10-30VDC supply, compatible with standard 24VDC industrial control power.

📘 Need the full method? NPN vs PNP Sensor Outputs Explained

When NOT to specify the H-M — and what to use instead

The target is a clear film, glass sheet, or other largely transparent material that only partially attenuates the beam

Why not: Through-beam detection in this series works purely by beam interruption; a target that doesn't sufficiently block the beam will not reliably switch the receiver's output.

Use instead: a diffuse-reflective or background-suppression sensor tuned to the target's edge or surface, rather than beam interruption

Only one side of the detection point can be wired and mounted

Why not: Through-beam (opposed mode) requires a separate emitter and receiver mounted facing each other along the same optical axis; there is no single-housing option in this series.

Use instead: a diffuse-reflective sensor that detects from one side only

Personnel guarding, machine-access safety interlock, or any life-safety function

Why not: The FAQs state explicitly that this is a general-purpose sensor, not designed, tested, or certified as a safety component.

Use instead: a safety-rated light curtain or safety interlock

Extremely space-constrained mounting where even an M12x63mm barrel and matching receiver won't fit

Why not: The smallest barrel in this series is M12x63mm (H122M/H125M); no sub-M12 through-beam option is offered here.

Use instead: a micro diffuse-reflective sensor in a smaller M3-M6 or M8/M12 threaded barrel

The application needs to discriminate the target's color, pattern, or surface feature rather than just presence/absence

Why not: Through-beam output only reflects whether the beam is broken, with no feature-recognition capability.

Use instead: a vision-based one-touch-teach sensor

Specifications we do not publish yet

We only publish a figure once we are confident it is true. The items below are still being validated through further testing and real-world customer feedback, so for now we would rather leave them open than guess. If one of them matters to your design, ask us for the latest validated status.

Ingress protection (IP) rating is not listed in the current specification table
Response time (operate/reset)
Light source type/wavelength
Minimum detectable object size / beam spot diameter
Hysteresis
Operating and storage temperature range
MTBF or expected service life
Cable/connector type

Frequently Asked Questions

What is the difference between a through-beam (opposed-mode) photoelectric sensor and a diffuse-mode sensor?

A through-beam sensor uses a separate emitter and receiver installed facing each other; the receiver switches when the light beam between them is broken by an object. Detection depends only on beam interruption, not on the target's color or reflectivity. A diffuse-mode sensor combines emitter and receiver in one housing and relies on light reflected back from the target, so its detection distance and reliability vary with the target's color, gloss and surface finish.

What sensing ranges are available in the H-M series?

Four range classes: H122M at 2 m +/-10% (M12), H125M at 5 m +/-10% (M12), H1805M at 5 m +/-10% (M18), and H1815M at 15 m +/-10% (M18).

What is the difference between the N1, P1, N2 and P2 suffixes?

N1 = NPN output, normally open (N.O.) only. P1 = PNP output, normally open (N.O.) only. N2 = NPN output with both normally open (N.O.) and normally closed (N.C.) outputs. P2 = PNP output with both N.O. and N.C. outputs.

Can this sensor detect dark, black, or transparent-edge objects?

Because through-beam detection only registers whether the light beam is interrupted (not how much light reflects back), it is not affected by target color or gloss the way diffuse-mode sensors are -- dark, reflective, or transparent-edge targets that still break the beam will be detected.

What is the physical size and thread of the M12 and M18 versions?

The M12 barrel is M12x63 mm; the M18 barrel is M18x73 mm. Both are threaded for standard nut mounting.

What material is the sensor housing made of?

Nickel-plated brass.

What supply voltage does this sensor require?

10-30 VDC.

Is this sensor a safety device, such as a safety light curtain or safety interlock?

No. This is a general-purpose through-beam photoelectric sensor for object/presence detection. It is not designed, tested, or certified as a safety component and should not be used as a substitute for a safety light curtain or safety-rated interlock.

Do I need to align the emitter and receiver precisely?

Yes -- as with any through-beam sensor pair, the emitter and receiver must be mounted facing each other along the same optical axis so the beam is unobstructed in the "clear" state; the threaded nut mounting is designed to hold that alignment once locked.

Can the same receiver give me both a run signal and an alarm signal?

Yes, on the N2 and P2 versions the receiver outputs both a normally-open (N.O.) and a normally-closed (N.C.) signal at the same time, so one sensor can feed both a positive-logic control input and a negative-logic alarm/interlock input.

Are through-beam and thru-beam photoelectric sensors the same?

Yes. Through-beam and thru-beam are two spellings for the same opposed-mode arrangement: a separate emitter faces a separate receiver, and the output changes when a target sufficiently interrupts the beam.