Cyclops™ Infrared Thermometers- Another Update

An Update on the Handheld IR Thermometer line that took over from DFPs*

Cyclops 100
Cyclops 100

The NEW Land Cyclops L family of high quality portable non-contact thermal infrared radiation thermometers provides spot temperature measurement with incredible accuracy and reliability.
The Cyclops product line is still going strong after nearly 30 years! (Note that the terms ‘radiation thermometer’ and ‘infrared thermometer” no longer appear on the Ametek-Land webpage that describes these measurement instruments! Clearly that’s an effort to simplify the terminology of these devices.)
Features such as a precision view of the measurement target spot with simultaneous digital display of temperature in the viewfinder, choice of operating and calculating modes, digital output and out of range alarms are provided as standard.
The Cyclops L family of non-contact portable thermometers introduce several new features to this instrument “dynasty”.
*With the introduction of the Minolta-Land Cyclops 52 in the 1980s, Land Instruments basically replaced the widely used Optical Pyrometer, AKA Disappearing Filament Pyrometer (DFP), sold world-wide by Leeds & Northrup Corporation (now defunct).

(ED NOTE: Land took over the full line when Minolta Camera Company merged with Konica and then withdrew from the camera business in the early 2000s.)
Below are some of the features of the latest models

  • On-board Data Storage – Up to 9,999 measurement points, stored inside the thermometer
  • Unique Route Manager – Ideal tool for plants with multiple locations, which you need to monitor on a regular basis. This includes pre-configured location settings for emissivity and window correction – no requirement to make a change to a Cyclops at different locations.
  • UKAS Calibration (option) – Full UKAS calibration in the Land on-site labs
  • New Logger Software – allows users to connect a Land Cyclops Portable thermometer to a personal computer or mobile device and view, analyse and record live temperature readings.
  • Added Protection – industrial rubber casing to withstand harsh environments for extended periods

The new Cyclops 055L Meltmaster is a dedicated high precision, portable non-contact thermometer, designed for accurate temperature measurement of liquid metal in foundries and steel plants.
The new Cyclops 100L is a general purpose, high temperature, portable non-contact thermometer, designed for accurate measurement of temperatures in the range 550 to 3000 °C/ 1022 to 5432 °F, in applications such steel, glass plus other high temperature applications.
The new Cyclops 160L is a general purpose, medium temperature, portable non-contact thermometer, designed for accurate measurement of temperatures in the range 200 to 1400 °C/ 392 to 2552 °F, in applications such steel, glass plus other medium temperature applications.
The unique features of the ruggedized Cyclops 390L portable non-contact thermometer make it the ideal instrument for accurate non contact temperature measurements in hydrocarbon-fuelled furnaces.
For more details on these latest models visit:
In The recent past we posted an article entitled: “New, Innovative IR Thermometer from the Minds of…on the original website (original webpage still at
Lost your Cyclops battery cover? Print one now!!!
AMETEK Land understand how easy it is in your busy industries to lose or break a small part like the Cyclops battery cover in day to day use.
AMETEK Land is again at the forefront of technology and have made the 3D design file (STL format) available to print on your own 3D printer.
No longer improvise a solution to hold the batteries in, just download the file, print and fit.
NOTE: For Cyclops B and L models only
Download the file by clicking here, print and fit it

Some Cyclops History

See if you can spot when the actual name changed from “Minolta-Land Cyclops” to just plain “Land Cyclops”. Given the fact that Land products are presently a part of the AMETEK product mix, it’s reasonable to expect a further designation change in the near future. (Hmmmm…“AMETEK Land Cyclops” sounds right)
In 2006 we wrote:

Cyclops 100
Cyclops 100

A “new” Cyclops™ Infrared Thermometer has been… created (that sounds best).
The Cyclops™ Model C100 from Land Instruments International has appeared on the scientific and industrial instrument marketplace without much ballyhoo and glitter.
Yet, its understated presence belies some remarkable things about it and its forebears.
Simply stated: it is the latest in a long family of Cyclopses*, the replacements for the venerable Optical Pyrometer. (It doesn’t sound quite right, but the root word is Greek, not Latin)
In its earliest incarnations in the 1980s as the Minolta-Land Cyclops were breakthrough devices, very innovative and actually more accurate in most uses than the century-plus, much venerated, old Disappearing Filament Optical Pyrometers.
The latest Cyclops, Model C100, is no less innovative in its own quiet way. It is the first portable IR thermometer, of which we are aware, to incorporate Bluetooth RS-232 communications capability.

A brief walk through Cyclops™ Past

When the first Cyclops Model 51 was sold, by the Land companies, then Land Pyrometers Ltd. in the UK and Land Instruments Inc. in North America, it was also understated, but powerful in the market.
In a few short years it and the even more capable Cyclops Model 52, displaced the Optical Pyrometer in all but a few uses.
Going back, first…in the beginning, in the late 1970s, Land Pyrometers, Infrared Division in the UK was developing their own high-temperature handheld IR thermometer to compete with the Leeds & Northrup (L&N) Optical Pyrometer which held a significant portion of the portable, noncontact temperature sensor market around the world.
(ED NOTE: Optical Pyrometers are also known familiarly as “Opticals” and “DFPs”. Some even called them “Paperweights”, they were so heavy.)
When, at around the same time, the Minolta Camera Company of Japan produced a prototype handheld, automatic thermometer that covered the most important portions of the industrial high temperature range.
In comparison with the Land planned unit, the Minolta design was compact, light, sleek and had SLR optics that were adjustable focus and gave a wide view of the observed area.
Then the two companies met.
Cyclops 51F
Minolta had a great, well-designed instrument but no experience in the industrial markets. Whereas, Land had years of experience in the metals, glass and ceramics markets and their first prototype was already getting known as “The Meat Tenderizer” by most of the people charged with marketing it.
The “Meat Tenderizer”  was basically rugged and very ugly. Add to that the difference in experience in blackbody calibration and traceability (Land~100%, Minolta~50%) and it was a match destined to be made.
A deal was struck and Land began selling the Minolta-made instruments around the world except for the Japanese home market; Minolta retained that.
The Cyclops 51 and 51F and their successors and variants, the Cyclops 52, 152, 41, 241, 252 etc. were smaller, faster, lighter, less expensive than Optical Pyrometers and didn’t require as much user judgment or training.
They produced results that were just as accurate, if not better than an optical pyrometer measurement, and often did better even in the hands of a new user.
The Cyclops had six other significant features that distinguished them mightily from “Opticals”.

  1. First, they had a precision emissivity adjustment, something DPFs lacked. That meant immediate correction for an object’s emissivity, assuming it was known. No look-up tables needed.
  2. Second, they had an electrical signal output that could be recorded by a portable or fixed chart recorder and/or datalogger, or actually used as an input to a control system. Opticals never had a recordable output. They depended on the operator to manually write down a reading.
  3. Third, they were, and still are (in the higher temperature models), orders of magnitude faster than Opticals. They could follow rapidly changing temperature readily and with the output feature, record them reliably.
  4. Fourth, the temperature reading was digital and could be “peak-picked” to capture high temperature transients. Opticals could never be adjusted rapidly enough to catch a rapid change or spike in temperature.
  5. Fifth, a Cyclops 51 or 51F took only one 9-volt transistor-radio battery, available almost everywhere, to power it. Even today, the latest models use only a few small, common batteries. Plus there is an auxiliary line-power supply for use in semi-continuous datalogging situations. The DFPs used extra-heavy dry cell batteries that added to their 11 pound weight.
  6. Sixth, and most useful, the Cyclops had the wonderfully crisp, clear adjustable-focus Minolta optics with the measurement spot defined by a small graticle in the field of view, and, the field of view included the temperature display. The newer models incorporate an auxiliary digital readout on the side of the case, too. The DFP had a red-filtered view of the object being measured and it was oftern difficult to view the surrounding area.

Cyclops combined innovative features, especially its short response time of 0.08 seconds, have yet to be fully matched by any price-competetive Infrared Radiation Thermometer in the last 20+years.
No wonder the Optical Pyrometer has effectively vanished! (The evaporation of Leeds and Northrup under General Signal Corporation’s watch did help speed things along a lot, too).
Other companies, notably Ircon, Inc, Chino Instruments and Mikron Infrared (formerly Mikron Instrument Company, Inc. – now a part of LumaSense Technologies) produced competitive devices. They helped hasten the slide of the Optical Pyrometer into the realm of instrument antiquity.
We know of only two companies that make or sell Disappearing Filament Optical Pyrometers, ostensibly on the basis of “better accuracy” because of the short wavelength of 0.6 microns.
If the users don’t yet know, there has been a special Cyclops model around for several years called the “Meltmaster” (C228) with an effective wavelength of 0.55 microns.
Ircon (now part of Raytek Corporation, subsidiary of Fluke, Corporation, in turn a subsidiary of Danaher Corporation) and Mikron Infrared (now part of LumaSense Technologies, Inc.)  have similar models, too. Plus Mikron makes two color, ratio thermometers in a portable configuration.

The Cyclops Family Picture Album:

Cyclops 51F

First there was one Cyclops, the Model 51, then very shortly thereafter there were two, the 51 and 51F.
Yes, there were initially two different models because they were mostly analog instruments and used different linearizer circuits.You know when there’s two of anything what can happen next.
You got it, a family was born! These (above) are however, the  “proud parents”.
(Images courtesy, where we found a few on sale)


The first all digital Minolta-Land Cyclops, Model C52. appeared a few years later and it really  smacked down the Optical Pyrometers in the marketplace!
The Model 52 was a revolution in silver-gray plastic. With switchable temperature scale, a, extremely wide temperature range, built-in math functions, super-fast and much more. All for a very reasonable price.
There are rumors of many, and this author knows of a few industry calibration labs, that began to have their Cyclops 52s certified at NIST as used in their own labs as Reference Standards for Radiation Temperature sources.
This was a major step forward in simplifying the traceability of radiation thermometer calibrations!
Land in the UK also offered traceable calibration certificates to the UK’s national calibration system at the time. (They did this in addition to offering a special line of secondary, traceable radiation thermometers and a set of primary fixed point reference cells at some key points on the ITS-90.)
Here’s an incomplete gallery of images and tidbits about the different Cyclops family members over the last twenty or so years.

Cyclops 390B Furnace Pro Infrared spot thermometer
From left to right, recent Cyclops Models are the New C100; the unit it replaces, the C153; the Meltmaster, C228; The Medium Temperature C241
From left to right, recent Cyclops Models are the New C100; the unit it replaces, the C153; the Meltmaster, C228; The Medium Temperature C241

Cyclops Mini – Image courtesy ebay 
From left to right, recent Cyclops Models are the New C100;
the unit it replaces, the C153; the Meltmaster, C228;
The Medium Temperature C241 and
the low temperature workhorse, the C300.
Cyclops-mini view

Cyclops Mini
The mini Cyclops  was part of the response of Minolta-Land to the popularity of very low cost general purpose instruments like the Raytek Mini in the 1990s, but they couldn’t compete effectively on price and appear to have been discontinued. (Note: The Raytek Mini appears to have been discontinued since Fluke took over, but the Fluke 62 Max seems to be its decedent in a market dominated by very low cost handheld IR Thermometers, many with a built-in laser pointer.)
Minolta/Land Cyclops Compac3
Minolta/Land Cyclops Compac3 (Image courtesy ebay)

There was an earlier low temperature Cyclops called the Compac 3. These can still be found regularly on
The Cyclops Family of the 1990s before the very low cost IR Temperature gun market heated up, included a wide range of products such as the Tele, with its very large mirror optical system for measuring near ambient temperatures at relatively long distance, shown in the background here and two special waveband units, one at 3,9 microns for looking through hot combustion gases and one at 3.4 microns for measuring thin plastics.
The high-performance C300 has survived nearly without change since the early 1990s. It, and the unique, but discontinued C300AF, an autofocus model that used the technology of Minolta’s autofocusing 35 mm cameras, were priced relatively high at the time and the latter didn’t last in the marketplace despite its incredible features and specifications.
Cyclops 152 with carrying case
Cyclops 152 as seen on

On the left is a side view of the Cyclops Model C152, the real workhorse of the family. For nearly 10 years, from the late 1980s to the late 1990s this was the unit used in many high-temperature places like metals processing plants, glass factories etc. The one pictured here was shown on ebay in December 2017 for the price of $1800!
It came with a sturdy carrying case, but its big innovation was the fully sealed body to resist the ingress of dust and moisture that were the biggest sources of instrument problems used in industrial plants.
Minolta engineered a complex, but reliable, inner-adjustable lens system that had no external screw threads.
Dirt didn’t “screw up” the threads anymore. It just made the best device on the market even more superior.
We are also still seeking a photo of the all-digital Cyclops 52 to add to this page to complete it. The case color and style of the Cyclops 52 was very much like the Cyclops 241 (shown above.)
Check back to see when we’ve found them.
Note: Cyclops is a Trademark of Land Instruments International Ltd.
Footnote: Why do I care about all this stuff?
Chalk it up to a combination of personal involvement and a misguided, possibly compulsive sense of history about temperature measurement devices, infrared ones in particular. I had a big hand in the introduction of the Cyclops to North America as the General Manager and then VP of Engineering of Land Instruments in the USA during Cyclops’s first, second and third generations.
I like to think that I helped make it a big part of the Land organization’s product portfolio by insisting on having it to sell in North America when the first prototypes were offered to Land by Minolta in the late 1970s.
Then, I actually got to use and see first-hand the remarkable accuracy, reliability and stability of the devices, especially the Cyclops 152, 241 and 300 Models, during the 1990s as the Senior Staff Engineer for Temperature Measurement at the now-closed LTV Steel Company’s Technology Center and the corporate manufacturing plants where we used them under some rough, industrial conditions.
At LTV Steel we not only recommended and/or actually equipped several in-house Calibration Laboratories with Cyclops models as certified traceable reference standards, but used them for process investigations and trouble-shooting on many hot-strip mills, taconite pellet process lines, reheat furnaces, annealing lines and process simulation devices.
They never failed in my experience of more than twelve years duration. I published several technical papers based in large part on field measurements in operating steel plants made with Cyclops family models.
Some of those very same devices may be still in use even though LTV Steel has evaporated as a corporation and most of its USA manufacturing plants are now part of the Acelor-Mittal organization.