Heat-seeking vision

Recent advances in infrared thermography systems used by the police and armed forces have opened up a wide range of condition-monitoring capabilities in the commercial sector.

From detecting swine flu to diagnosing problems with electronics, the technology has become an indispensable tool for monitoring and diagnosing problems in an ever-increasing range of industries. Conservative estimates indicate an average saving of £7 derived from every £1 invested in the technology, and the latest range of cameras is set to increase this figure.

Currently, most infrared thermography systems can provide image temperatures from -20°C to +500°C, with accuracies of around ±2% at 30°C. They work by recording the infrared radiation emitted by objects, which increases with the temperature.

In defence, the cameras are used to detect human-sized targets at a distance of about 20km or during coastal surveillance tasks for the detection of vessels. However, a growing need to improve their accuracy and range is driving the next generation of condition-monitoring systems.

FLIR, a global manufacturer of thermal-imaging cameras, has developed a line of cameras that it claims can meet this challenge. Its P-series targets pixel size, sensitivity and lens power – three areas that have traditionally been weak in thermal imaging. The P-series features a larger germanium lens to allow more infrared radiation to reach the detector. A higher-resolution camera and improved thermal sensitivity, ranging from 65mk to 45mk, provide better temperature difference accuracy.

These features are crucial in applications such as building and machine condition monitoring, where temperature differences could highlight costly and dangerous flaws within the system. As a result, Surrey-based loss-prevention specialist Global Risk Consultants has taken on a FLIR P-Series thermal-imaging camera for the infrared inspection of low-voltage equipment.

According to Daniel Gosden of Global Risk Consultants, of all the electrical faults he reports, around 95 per cent are due to poor connections. Poor environmental conditions can also repeatedly cause faults and failures. ’These problems show up really well on the camera screen,’ he said. ’They are simple fixes that cost little to repair if caught in time and thermal imaging is the best way to achieve this.’

Predominantly, the role of the cameras is in the condition monitoring of capital equipment and associated electrical systems, but they are also being used to check the integrity of insulation to minimise energy loss.

In a recent contract undertaken by Global Risk Consultants, an infrared survey with the P-Series camera showed a very low-temperature fault on a low-voltage connection in the communications room. ’The rise was just 6°C, which I would normally discount,’ said Gosden. ’But because this facility serves the entire European sales department of this company, I was mindful of the high potential losses that could ensue in the event of a power loss. The problem was tagged for further investigation.’

Chubb Insurance has also benefited from the technology. The group estimates that investment in infrared thermography has prevented losses that run into millions of pounds. Chubb employs about 70 certified thermographers worldwide, which it assigns to check the health of customers’ electrical and mechanical assets to minimise fire risk and costly downtime.

Since implementing the service in 1997, the company has maintained a database of every hotspot detected. Against each of these surveys, it attributes a cost of potential property loss and business interruption should the defect have been allowed to develop. The company estimates that averted losses to date are in excess of £3.5m and rising.

Overall, the group believes that the technology has a vital role to play in the business and commercial sector. It is estimated up to 30 per cent of all industry fires can be attributed to an electrical fault. Chubb’s thermal-imaging cameras allow it to spot the signs of a developing fault without the need to interrupt the production or business process.

Neil MacLeod, risk engineer at Chubb, said: ’As well as preventing catastrophic failure, it also allows us to help the customer minimise downtime and use maintenance resources effectively… Almost without exception, every one of our infrared customers has commented on the capabilities of the non-invasive camera and the visual impact of thermography.’