Mission control
September 21st 2005 IR thermography condition monitoring becomes truly predictive only when you reach the other side of the panel, says Ross Kennedy, MD of QHi Systems. Now with SCADA capability, he says ExerTherm IR technology means mission critical plant maintenance is no longer a gamble. Brendan Coyne reports
Although accepted as industry standard, protecting mission critical plant with non-contact thermal imaging has its risks: line of site is required and only components immediately adjacent to the external surface can be accurately measured. Effectively, only a percentage of the whole is continuously monitored. Planned maintenance can offer a snapshot of ‘deeper’ component condition – but unplanned problems can and generally do occur between scheduled service intervals.
QHi Systems MD, Ross Kennedy, believes the only real solution is to put sensors inside rather than outside – or far away from – critical parts. He says ExerTherm IR technology (using plastic-bodied sensors that require no power) enables this. Designed originally for mission critical switchgear and, for example, currently used buy HSBC and IBM’s data centres, Kennedy says ExerTherm can monitor any kind of key plant which increases or decreases in heat as a symptom of fault.
He claims the broader industrial sector is now beginning to take an interest due to compatibility with standard systems.
SCADA compatible
Kennedy says it is suitable for any mission critical application – and can be used on mechanical equipment: “Gear box motors; pumps; valves; air handling systems; refrigeration systems; steam traps – all of these will provide an abnormal thermal signature for fault or malfunction,” he explains. “But we are [only now] looking more closely at the industrial market because it integrates with SCADA systems – which it previously didn’t. That will act as a huge draw for the industrial sector because we can supply the data in a way that the industry wants and integrate it into their existing systems.”
There are four levels of integration, from simple alarm messaging through to full integration as part of an open system framework (meaning it can essentially plug in to anything).
Cost
Although difficult to give an exact unit cost, Kennedy says the total outlay is between £100 and £200 per sensing point. “But that’s the total system cost – hardware, software, everything,” he says. “And we’re not suggesting that thermal monitoring on every termination is needed – that’s nonsensical. If it’s mission critical, it should be monitored.”
“However there is a payback: if you look at what companies spend on trying to mitigate the risk of downtime failure, the majority is spent on post failure activity i.e. UPS and fire detection and suppression. Companies are spending up to 30% of the budget on trying to save the situation post failure: You don’t have to be an engineer to work out that it makes more sense to spot a failure before it happens.”
Retrofitting
While designing the sensor into new equipment is QHi’s preferred route, Kennedy explains it can easily be retrofitted into the harshest environments: “We were approached by XX cruise lines to fit out the engine room of a luxury liner. Their specifier told us they had tried thermography before – without any meaningful results. To win the business we had to agree that if it didn’t work as planned, we would remove the entire system at our own cost. We agreed, everything worked and we got paid.” he says. “So although it’s new to the industrial sector this is proven technology – no-one will be walking the gangplank.”
Multiple monitoring methods
QHi also uses a range of other sensors (cable sensors, air temperature sensors, contact sensors etc.) in conjunction with IR so that, wherever it is not practical to place an IR sensor, other methods can be applied. “Which will tell you equally well that there is going to be a problem,” says Kennedy.In September QHi also announced a strategic alliance with vibration monitoring specialist, SPM. The two are collaborating to produce a condition monitoring module combining their respective expertise. “They are not dependant on each other, so you can have a combined system or use them separately,” explains Kennedy.
A case of giving the customer whatever they want.
Exertherm explained
ExerTherm is based on patented small, plastic-bodied, non-contact infrared sensors which require no power. This means they can be placed inside an enclosure to continuously monitor any component regardless of location.
By solving the power problem, QHi MD Ross Kennedy says they also do way with an amplifier, resulting in lifetime calibration. Based on five year sales, he also claims they have over 1,000 years MTBF (mean time before failure). Exertherm’s specification by Eurotunnel for its fire detection system (which required a minimum of 15 years without maintenance) is a concrete example of its durability.
Placed inside the enclosure or plant, sensors are linked back via data acquisition cards to a PC or server – enabling on-going trend analysis, reports and graphs. Two separate alarm levels per sensor (warning and alarm) automatically activate when pre-set temperature limits are breached.
SCADA compatible, it can integrate with over 400 BMS/bus protocols. QHi says it is easy and inexpensive to retrofit to mission critical equipment. More articles from QHI Group: | 
