LT: 45°C* to 300°C
PT: 100°C to 400°C
MT: 250°C to 1000°C
HT: 450°C to 2000°C
GLT: 50°C to 1000°C
GHT: 200°C to 1650°C
-40°C to 1000°C
15:1 (with LT or PT temperature range)
25:1 (with MT or HT temperature range)
75:1 (with MT or HT temperature range)
PUA5 models: 25:1
PUA8 models: 30:1 or Close Focus ø 5 mm @ 100 mm
Two-wire 4 to 20 mA (linear with temperature)
Via PC port conforming to USB 2.0
PUA2 models: ±1% of reading or ±2°C, whichever is greater
PUA5 and PUA8 models: ± 1°C or 1% of reading, whichever is greater
±0.5% of reading or ±0.5°C, whichever is greater
Adjustable 0.1 to 1.0 via software
PUA2: 2.0 to 2.6 µm
PUA5: 5 µm
PUA8: 8 to 14 µm
24 V DC (28 V DC max)
Max Loop Impedance
900 Ω @ 24 V DC
Maximum Span (analogue output)
Full temperature range
Minimum Span (analogue output)
Software Specifications (CalexConfig)
Temperature display, scrolling temperature chart, sensor configuration, data acquisition with scheduled start, on-screen alarm
Data log file format
.csd (comma separated text format, may be imported to spreadsheet software such as Excel)
Data transmission protocol
Modbus over USB (it is possible to communicate with the sensor for temperature measurement and configuration using third-party software. Protocol information is provided in the instruction manual.)
Ambient Temperature Range
0ºC to 70ºC (cooling option available for use in higher ambient temperatures)
95% max. non-condensing
Please note: The given measured spot size contains 90% of the energy detected by the sensor. We normally recommend the target is at least twice as large as the given measured spot for maximum accuracy.
Sensors may be used at longer distances than the above diagrams show. There is no maximum measurement distance in clean air; this is because PyroUSB sensors detect only the wavelengths of infrared radiation that are not absorbed by the atmosphere.
Ø 27.6 x length 61 mm including cable glands
M20 x 1 mm pitch, length 15 mm
Weight with Output Cable
Output Cable Length
1 m (longer cable available to order)
Minimum Measurable Temperature (PUA2-151-LT only)
Graph showing the minimum measurable object temperature (Tmin), determined by surface emissivity (ε) and sensor temperature (Ts). Applies to model PUA2-151-LT only.
Electromagnetic Compatibility Standards
Conforms to EN61326-1, EN61326-2-3 (Electrical Equipment for Measurement, Control and Laboratory Use – EMC Requirements – Industrial)
The PyroUSB’s choice of measurement wavelengths allows it to be used in a wide range of industrial applications.
The short-wavelength PUA2 provides a more accurate reading on reflective metal surfaces, such as iron and steel, than longer-wavelength sensors. Applications include general steel strip temperature measurements at low temperatures, steel temperature measurement before the reheat furnace and temperature at the coiler on the hot rolling mill
Extrusion, Forging and Casting
PUA2 models are ideal for measuring the temperature of steel dies and workpieces in extrusion, forging and casting applications
Measure the temperature of hot food products inside glass containers from 45°C to 300°C using PyroUSB PUA2 models. The pyrometer measures through the glass; readings can be taken on-line without interrupting production.
Other applications include tunnel pasteuriser temperature monitoring, and temperature of bare stainless steel surfaces on food manufacturing machinery, such as hot rollers and conveyors
PyroUSB PUA2 sensors allow non-contact measurement of ceramic, carbon, iron and steel brake disc temperatures between 45°C and 2000°C on brake test rigs
PUA2 models can monitor brake disc surface temperature in wind turbines, to help warn of overheating and optimise cooling cycles. PUA8 models measure non-reflective parts of the turbine, such as gearbox and bearing housings. Non-contact infrared sensors can monitor the temperature of vibrating parts while being isolated completely from vibration.
Bearings, gearboxes and shafts
Non-contact temperature measurement of bare steel surfaces: the PyroUSB PUA2 is less susceptible than long-wavelength sensors to errors caused by reflections
Furnaces and ovens
The high-temperature capability of the PyroUSB PUA2 is ideal for measuring the temperature of hot objects inside furnaces and ovens, including steel mill heat treatment furnaces.
Furnace-heated or induction heated pipe temperature measurement, at the preheat stage, before coating (using model PUA2)
Paper, Print and Converting
PUA2 models: Monitoring of the surface temperature of hot bare steel rollers, such as steam-heated dryer cylinder temperature in paper manufacturing.
PUA8 models: Accurate measurement of the paper temperature is easy, even at very low temperatures.
Temperature readings may be used for control and alarm.
The 4-20 mA analogue output and USB output may be used individually, or both may be used at the same time.
For software, see www.calex.co.uk/software
4-20 mA output
USB and 4-20 mA outputs together
USB output only
[PUA2] Short Wavelength, 2.2 µm, for measuring reflective metals and high-temperature objects
[PUA5] 5 µm, for measuring glass surface temperature (Minimum Order Quantity applies for PUA5 models – contact Calex for information. Also consider the PyroCube G)
[PUA8] General Purpose, 8 to 14 µm, for most other applications
 15:1 divergent optics (LT & PT models only)
 25:1 divergent optics
 75:1 divergent optics
 25:1 divergent optics
 30:1 divergent optics
[CF] Close-focus optics (focal spot size 5 mm at 100mm distance)
[LT] 45°C to 300°C (151 models only)
[PT] 100°C to 400°C (151 models only)
[MT] 250°C to 1000°C
[HT] 450°C to 2000°C
(blank) All models: -40°C to 1000°C
[GLT] 50°C to 1000°C
[GHT] 200°C to 1650°C
(blank) Sensor without cooling
[WJ] Air/water cooled jacket with air purge collar