Impac series petrochemical pyrometers

The Quasar 2 can reliably detect pilot flames and flaring events at distances of up to about 400 m (approximately a quarter mile). By selecting one of five high-resolution optical lenses, users can optimise the field of view and spot size for their specific flare stack height, ensuring flame detection even from very far away.

The Quasar 2 is designed to filter out false alarms caused by momentary flame loss or environmental factors. It incorporates an adjustable alarm delay circuit – this means the sensor won’t trigger a "flame out" alarm unless the flame signal is lost for a sustained period that you define. In addition, the Quasar’s electronics automatically adjust for rain, fog, or snow and for target movement (such as a flickering flame), preventing nuisance alarms due to brief disturbances.

Yes. The Quasar 2’s infrared sensing technology can detect hydrocarbon flames as well as hydrogen flames, even though hydrogen fires are not visible to the naked eye. It operates in spectral bands where the hot water vapour and combustion by-products of a hydrogen flame emit infrared radiation. This allows the Quasar 2 to monitor for the presence of a hydrogen flame on a flare stack pilot, enhancing safety for processes that may burn hydrogen or hydrogen-rich gases.

"Smart FMA" stands for Smart Flame Measurement Algorithm, and it’s a feature unique to the Pulsar 4 Advanced pyrometer. This algorithm continuously compensates for the optical interference of an open flame when measuring furnace temperatures. In practice, flames (the burning gas) can cause false high readings of gas temperature (GT). Smart FMA corrects for this by transparently calculating and removing the flame’s effect on the measurement. The result is a more accurate true gas temperature and refractory temperature (RT) reading, even when an active flame is present between the sensor and the furnace interior.

The Pulsar 4 Advanced is equipped with two separate infrared detectors, each tuned to a different wavelength band. One detector is configured to measure the temperature of the furnace refractory lining (the wall), while the other measures the combustion gas or flame temperature. By using a dual-wavelength approach, the instrument can provide two readings at once (RT and GT) in real time. This simultaneous measurement helps operators quickly see the furnace’s thermal state – ensuring the refractory isn’t overheating while also monitoring the flame/gas temperature – all with a single, integrated pyrometer device.

Yes – both the Quasar 2 and Pulsar 4 are built for hazardous locations and carry multiple explosion-proof certifications. They are housed in flameproof Ex d enclosures certified under international standards like ATEX and IECEx (Zone 1, gas group IIB + H₂, T4). They also meet North American standards (CSA/FM) for Class I Division 1 areas (including gas groups B, C, D). In short, they can be safely installed in petrochemical zones where flammable gases or vapours are present, without risking ignition. The Quasar 2 is additionally rated SIL 1, indicating it meets a certain safety integrity level for reliable performance in critical safety systems.

Each device offers standard industrial output signals for easy integration. The Quasar 2 provides a 4–20 mA analog output that is typically used in a "switched" mode (e.g. 20 mA = flame on, 4 mA = flame off). The Quasar 2 Advanced version adds a proportional 4–20 mA output representing flame intensity and also a relay contact output. The Pulsar 4 Advanced provides two continuous 4–20 mA analog outputs (which can be assigned to the refractory and gas temperature readings). In addition, the Pulsar 4 Advanced supports digital communication: it has an RS485 interface, and in the advanced model it also supports HART 7 protocol over the 4–20 mA channel. These options allow direct connection to PLC/DCS systems and asset management software for remote monitoring and configuration.

Very little. Both the Quasar 2 and Pulsar 4 are engineered to be nearly maintenance-free during operation. Their stainless steel housings and optics are built to resist environmental fouling. There are no moving parts inside the sensors, and calibration is stable over long periods. In practice, maintenance is limited to occasional cleaning of the optical window/lens if it becomes dirty (for example, due to soot or dust accumulation) and periodic verification of the alignment. The modular design (especially of Quasar 2’s opto-electronics) makes it easy to service or replace components if necessary. Overall, routine checks and perhaps annual calibration verification are sufficient – there is no frequent maintenance needed, which minimises downtime in continuous processes.

The standard Pulsar 4 is a single-channel infrared pyrometer – it can be configured to measure either the gas temperature or the refractory temperature in a furnace, one at a time. In contrast, the Pulsar 4 Advanced is a dual-channel unit that measures both simultaneously (one channel for gas, one for refractory). The advanced model also includes the Smart FMA algorithm (for flame interference correction) which the standard model lacks. Additionally, the advanced version provides more output options (such as HART digital communication) whereas the standard Pulsar 4 primarily offers a basic analog output. In summary, if you need dual temperature readings and the highest accuracy under flame conditions, the Pulsar 4 Advanced is the better choice, whereas the standard model is suited for simpler or direct replacement applications where only one temperature point is needed.

Yes. The Pulsar 4 was designed as a drop-in replacement for the legacy Pulsar II units. It has a similar mechanical form factor and mounting interface, so it can fit into the existing port or sight-tube on the furnace. The electrical connections and power requirements are also compatible – the Pulsar 4 has an integrated power supply that can accept the same voltage inputs (24 V DC or standard AC mains) used by older models. This means you can swap in a Pulsar 4 in place of a Pulsar II without major changes to wiring or infrastructure. Once installed, the new unit offers improved performance and additional features (especially if using the Advanced version), all while maintaining continuity with the previous system’s setup.