What it is

The Optris CTi 1M is a miniaturized two-piece infrared thermometer for non-contact temperature measurement of metal from 662 °F to 3,992 °F (350 °C to 2,200 °C). It measures at a short 1.0 µm wavelength, which reduces temperature reading errors on surfaces with low or unknown emissivity. That makes it well suited to metals, secondary metal processing, metal oxides, and ceramic materials. The sensing head is only 0.55 in (14 mm) in diameter and 1.10 in (28 mm) long. It runs up to 257 °F (125 °C) ambient without cooling and connects by cable to a separate electronics box. Exposure time is 110 µs, and measuring spots start at 0.06 in (1.5 mm).

• Temperature range: 662 °F to 3,992 °F (350 °C to 2,200 °C) across four models
• Spectral range: 1.0 µm
• Optical resolution: 15:1 (1MXL), 40:1 (1ML), 75:1 (1MH and 1MH1)
• Smallest spot: 0.06 in (1.5 mm) with close-focus optics
• Exposure time: 110 µs (90%); response time 320 µs (90%)
• Sensing head: 0.55 in (14 mm) diameter × 1.10 in (28 mm) length; up to 257 °F (125 °C) ambient without cooling
• Environmental rating: IP67 (NEMA-4)
• Outputs: 0/4–20 mA, 0–5/10 V, thermocouple K, alarm; built-in USB
• Power supply: 8–36 V DC / 1.2 W

What it is used for

Some of the use cases for the Optris CTi 1M include:

• Metal temperature measurement: non-contact measurement of hot metal surfaces from 662 °F (350 °C) up to 3,992 °F (2,200 °C).
• Secondary metal processing: monitoring metal temperatures in downstream processing steps.
• Metal oxides: measuring oxidized metal surfaces, where the short 1.0 µm wavelength reduces errors from low or unknown emissivity.
• Ceramic materials: high-temperature measurement of ceramics.
• Small targets: measuring spots down to 0.06 in (1.5 mm) with close-focus optics.
• Tight installations: mounting the 0.55 in (14 mm) head in confined or hot locations, with the electronics box sited remotely.

The model range

Temperature ranges are scalable via the programming keys or software and app. Full optical, electrical, and environmental data is in the Specifications tab.

Key features

• Short 1.0 µm wavelength: reduces temperature reading errors on surfaces with low or unknown emissivity.
• Miniature sensing head: 0.55 in (14 mm) diameter and 1.10 in (28 mm) long, with an M12 × 1 thread, so it fits in tight spaces.
• High-temperature head without cooling: the sensing head operates up to 257 °F (125 °C) ambient.
• Standard or close-focus optics: standard focus for distance measurement, or close focus for spots down to 0.06 in (1.5 mm) at 4.3 in (110 mm).
• Separate electronics box: with an LCD display showing 0.1 K resolution and programming keys.
• Flexible outputs: 0/4–20 mA, 0–5/10 V, and thermocouple K analog outputs, an alarm output, and built-in USB.
• Optional fieldbus interfaces: EtherNet/IP, Profinet, EtherCAT, Ethernet TCP/IP with Modbus TCP, Modbus RTU, RS485, RS232, or two optically isolated relay outputs.
• Three programmable I/O pins: external emissivity adjustment, ambient temperature compensation, uncommitted value, trigger (reset of hold functions), or alarm output.
• Signal processing: peak hold, valley hold, and averaging, plus extended hold functions with threshold and hysteresis.
• Software and app: configuration through optris CompactPlus Connect software or the IRmobile app.

Why engineers pick it

Built for hot metal. The short 1.0 µm wavelength reduces temperature reading errors on surfaces with low or unknown emissivity, across metals, metal oxides, and ceramic materials.

Fits almost anywhere. The 0.55 in (14 mm) sensing head runs at up to 257 °F (125 °C) ambient without cooling, with the electronics box mounted remotely.

Fast measurement. A 110 µs exposure time and 320 µs response time, with NETD down to 160 mK on the 1MH1.

Flexible integration. Analog outputs, built-in USB, three programmable I/O pins, and optional industrial Ethernet, fieldbus, and relay interfaces.

Frequently asked questions

Can I use the CTi 1M as a 2-wire sensor?

No. Do not connect a supply voltage to the analog outputs, as this will destroy the output. The CTi 1M is not a 2-wire sensor. If you need a two-wire device, review the Optris CSmicro series instead.

What distance-to-spot size ratio is correct for my application?

The size of the measuring object and the thermometer's optical resolution determine the maximum distance between the sensing head and the object. To prevent measuring errors, the object should fill the field of view of the optics. The spot should always be the same size as the object or smaller.

Which settings change if an external close-focus lens is used?

The optional CF lens allows measurement of small objects. When it is fitted on the CTi 1M, transmission must be set to 0.92. Note that this differs from the other CTi sensors, which use 0.78, because the CTi 1M measures at 1.0 µm rather than 8–14 µm. The figure is an average characteristic value and may scatter between units, so determine it experimentally if your application requires it.

Can I shorten the cable between the sensing head and the electronics box?

On the CTi 1M the sensing head cable can be shortened by a maximum of 9.8 ft (3 m). This differs from the other CTi sensors, where shortening is discouraged and introduces an error of about 0.1 K per metre.

How do I exchange the sensing head?

Heads are connected and calibrated at the factory. Any exchange of sensing heads and electronics is possible within a given model group. Every head carries a specific calibration code printed on the head cable, and that code must be stored in the electronics box for correct temperature measurement and sensor functionality.

How can I improve the noise amplitude of the sensor?

Do not move the head cable during measurement. Use shielded cables only and ground the sensor shield. Avoid ground loops and related signal interference in industrial environments. It may be necessary to interrupt the ground connections inside the electronics box by switching the internal jumper to another position. Review the manual before doing so.

Accessories

• CF-lens (ACCTCFHT): close-focus lens for small spot measurement, M12 × 1.
• Mounting bracket, fixed (ACCTFB): fixed bracket for mounting the sensing head.
• Air purge collar with integrated CF-lens (ACCTAPLCFHT): keeps the lens clear in dusty or fume-laden process environments.

Configuring and scaling

Select the model, optics, and cable length on this page and use Request Quote to order. Cable lengths are 9.8 ft (3 m) standard, 26.2 ft (8 m), or 49.2 ft (15 m). Contact W5 for anything the selector doesn't cover, such as optional digital interfaces, relay outputs, and accessories.

Scope of supply

CTi 1M with a 9.8 ft (3 m) cable, mounting nut, and quick start guide.

Get the CTi 1M specified and supplied

W5 Engineering supplies Optris infrared temperature measurement products. We match the model to your temperature range, target size, and working distance, then specify the optics, cable length, and any fieldbus interface you need. Contact us with your process temperature and measurement distance and we will return a configuration recommendation and quote.