PyroBus (Discontinued – see PyroMiniBus)
RS485 Modbus Pyrometer - Superseded by PyroMiniBus
Alternative Product:PyroMiniBus

Sensor Features

  • Temperature range: -20°C to 500°C
  • RS485 Modbus interface
  • Up to 247 sensors per network
  • Connect to an existing Modbus PLC or a Calex touch screen terminal
  • Fully configurable for emissivity, averaging and signal processing

Key Feature Tags

Read more

General Specifications

Temperature Range
-20°C to 500°C
RS485 Modbus RTU
±1% of reading or ±1ºC whichever is greater
± 0.5% of reading or ± 0.5°C whichever is greater
0.2 to 1.0
Response Time, t90
240 ms (90% response)
Spectral Range
8 to 14 μm
Supply Voltage
12 V DC nominal (6 to 13 V DC)
Supply Current
50 mA max.
Baud Rate
9600 baud *
Modbus Data Format
8 data bits, no parity, 1 stop bit *

Field of View Diagrams

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 the PyroBus detects only the wavelengths of infrared radiation that are not absorbed by the atmosphere.

Mechanical Specifications

Stainless Steel
18 mm diameter x 103 mm long
Thread Mounting
M16 x 1 mm pitch
Cable Length
1m (longer lengths available to order)
Weight with Cable
95 g

Environmental Specifications

Environmental Rating
Ambient Temperature Range
0°C to 70°C
Relative Humidity
95% max. non-condensing

Electromagnetic Compatibility Standards

EN61326-1, EN61326-2-3 (Electrical Equipment for Measurement, Control and Laboratory Use – EMC Requirements – Industrial)

The PyroBus may be installed as a standalone network of sensors, or integrated into an existing Modbus network. Sensors may be connected in a daisy-chain via junction boxes to a single network bus cable, which can significantly simplify cable runs and reduce the cost of cabling compared to using analogue sensors.

For continuous monitoring, PyroBus sensors are significantly lower in cost than thermal imagers, and provide instant, real time temperature data.

There are applications for the PyroBus in a wide range of industries. It is ideal anywhere RS485 Modbus instrumentation exists, or anywhere a large network of sensors is required. For example, some typical uses include:

Typical Applications

Power distribution
The PyroBus is ideal for monitoring the temperature of busbar joints in switchgear cabinets. For a three-phase switchgear box, 6 PyroBus sensors are used to monitor the busbar temperature for each phase on the input and output sides, in conjunction with a PM180 hub for logging and alarms.

For larger requirements, up to 247 sensors can be connected on a single RS485 Modbus network, so whole power distribution rooms can be monitored using networks of these digital pyrometers.
The PyroBus has peak/valley hold processing capability for conveyors and production lines, and the RS485 Modbus interface makes it ideal for food applications where temperatures at several points must be monitored simultaneously.
Corrugated board manufacturing
A single network of sensors can monitor the web temperature along an entire corrugator, with local displays for each single facer, double backer and triple stack preheater, and centralised monitoring in the control room. For areas of high ambient temperature, air cooling may be used, or high-temperature PyroMini models may be incorporated on the same Modbus network, either via the PM180 hub or via existing Modbus instrumentation.
The PyroBus is ideal for measuring plastic sheet preheat temperatures in multiple locations on thermoforming machines, with all temperatures displayed simultaneously on a single screen and used for temperature control and monitoring
Large systems of PyroBus sensors can monitor the paint curing process at multiple points along the production line. In environmental test chambers, a network of PyroBus sensors can build up a map of temperatures around the entire vehicle
Condition monitoring
A single network of sensors can monitor all the bearing temperatures on a machine, a whole runout table, or even in the whole factory. The PyroBus is ideal for measuring the temperature of painted metal surfaces including bearing housings, driveshafts, rollers and gearboxes
Infrared curing
Arrays of sensors fitted on a rig of infrared curing lamps ensure an even temperature profile along the part being cured. Surface coatings, paint and epoxy are ideal target materials, among many others.
Gas cylinder filling
A PyroBus sensor is used to measure the temperature of every gas cylinder on the filling rig, and all temperatures are monitored to improve repeatability in the filled volume and improve filling efficiency

Electrical Installation

Dimensions (mm)

PM180 6-Channel Hub

6-channel touch screen hub for temperature display, alarms, configuration and data logging. Isolated RS485 Modbus master and slave interfaces allow multiple hubs to be connected to a larger network. Optional modules provide analogue and relay outputs.

Air Purge Collar

The air purge collar is used to keep dust, fumes, moisture and other contaminants away from the lens. Air flows into the fitting on the side and out of the aperture at the front.

Fixed Mounting Bracket

The L-shaped fixed mounting bracket offers a rigid support for the sensor and allows fine rotational adjustment about one axis.

Adjustable Mounting Bracket

The adjustable mounting bracket consists of a fixed mounting bracket plus another L-shaped bracket. When assembled as shown, the adjustable mounting bracket offers a rigid support for the sensor and allows fine two-axis adjustment.

Air/Water Cooled Housing

The air/water cooled housing allows the sensor to withstand ambient temperatures above the normal 70°C limit. Depending on the degree of cooling required, air or water may be used as the cooling fluid. To prevent condensation forming on the lens, an air purge collar is included with this item. The air/water cooled housing must be ordered with the sensor and cannot be fitted by the user.

Laser Sighting Tool

The Laser Sighting Tool screws onto the front of the sensor during installation and shows precisely where the sensor is aiming. Once the sensor has been aimed at the centre of the target and locked in position, the Laser Sighting Tool can be removed. The laser is operated via a latching push button on the front of the tool.

Dual Laser Sighting Bracket

The Dual Laser Sighting Bracket is a sturdy mount for the sensor and provides continuous target sighting while measurements are being taken. Two parallel lasers indicate the centre of the measured spot and are controlled by a remote switch on the electronics module.

Protective Plastic Window

When fitted over the lens of the sensor, the protective plastic window in stainless steel holder provides mechanical protection and helps retain fragments of lens in case of damage. Adjust the sensor’s emissivity setting to compensate for the presence of the window for maximum accuracy. This accessory is ideal for the food and pharmaceutical industries.

Ordering Information