Lasermet’s ADM1000 Laser Power Meter linked to a PC with one of the laser pistols
Equipment Controller, Ben Candy, checking a laser pistol with Lasermet’s laser power meter
Steve Candy, the combined event manager for LOCOG, the London 2012 organising committee, describes how the Laser Power Meter from Lasermet – the laser safety specialists - was used to help ensure laser pistols used in the Modern Pentathlon provided competitors with a level playing field.
‘Modern Pentathlon is five events comprised of fencing, swimming, horse-riding, shooting and running. The five disciplines are all completed in a single day, with the shooting and running now combined into one final event. In 2010, the sport changed from pistols firing pellets to laser pistols for the shooting discipline.
‘All the points are added up from the fence, the swim and the ride, and the points’ difference equates to a time handicap for the final combined event. So, whoever crosses the finish line first is the winner. This makes it very exciting with a tremendous finish. In the shooting, the lead can change several times depending on how accurate or inaccurate the athletes are with their shots. The Great British women have traditionally done very well at the Olympics winning a medal or two at every Olympics since Stephanie Cook won the first women’s gold in Sydney in 2000. Samantha Murray won silver at the London 2012 Games.
‘Last year, the sport’s governing body, the UIPM, decided to change to laser pistols, for many reasons. There are restrictions in some countries with firing a pellet and the governing body wanted to move to lasers so the sport could be held anywhere. In some countries, younger children aren’t allowed to shoot a pistol at all. Moving to a laser opened up the opportunity to get some younger athletes into the sport.
‘It was an emotional time for the sport; many traditionalists didn’t want the change.
The laser pistol was introduced and competitions run throughout 2011, including the World Cup and World Championships. There were some issues around the new technology and for the London Olympics we wanted to eliminate as many as possible. With any changes in a sport it takes a little while to settle down, but it was the Olympics and we didn’t want any issues so we spent a lot of time deciding how to resolve them. This included cabling / communications, protection from the elements and also the laser. ‘In 2011, an agreement was made by the UIPM on the laser specifications so that different suppliers could provide different kit for the pistols and the targets and for them all to work. Because there hadn’t been any real testing at competitions up until that point, the laser shooting was open to both abuse and safety concerns. I wanted to make sure the athletes had a level playing field and that nobody had tweaked the lasers and make them more powerful or fire a longer shot etc.
The women’s warm up on range.
‘What I particularly wanted to test was the length of the shot and the power. There were other aspects I would have liked to test like the trigger delay mechanism and the waveform of the beam, but these were less critical. I wanted to make sure the athletes had a level playing field.
Typical pulse from competitors’ laser pistol displayed on screen
Equipment at the ready on the range
GB’s Samantha Murray, Silver Medallist, in the Women’s Modern Pentathlon
Range during preparation
The Range and Queen’s House
‘In addition to Equipment Control testing, having a piece of equipment that can determine whether the laser pistol is firing correctly during the event is invaluable. Athletes won’t say they missed; laser manufacturers won’t say there’s anything wrong with the laser and the target manufacturer will deny any fault as well. I have to make decisions very quickly – for instance, I’m allowed to move an athlete if it’s a technical malfunction. If it’s a pistol that doesn’t work, that’s kit, that’s unlucky. They’re allowed a second pistol, but it’s part of the sport. The same would apply if the épée fails in fencing, they have to go and fix it and they’ll lose a few points because of it. In the riding, the athletes select a horse they haven’t ridden before. So, if the pistol fails that’s their fault, but if the target fails then that’s not the athlete’s fault and in the current rules I’m allowed to move them to another firing point. I have to make that decision very quickly, so I needed a piece of kit to do both: make sure there was a level playing field and also to be able to make snap decisions on the field of play.
‘With Lasermet’s laser power meter, the laser power and length of shot can be displayed on a PC, but also on the meter itself, which is ideal for testing on the field of play. During the equipment testing the day before the event, we could fire the pistols into the meter, get a reading up on the PC and create a file in the athlete’s name. We had a register of the power and length of shot of each athlete’s pistol at equipment control the day before and on the day. We then lock the pistols away, so the athletes only get access to them during practice sessions.
‘The testing went really well. There was a norm setting for the laser pistols derived from the World Championships. I wanted to make sure no one was in the extreme. There were some pistols that we rejected and made sure they were readjusted.
‘For me, the power meter proved an excellent piece of equipment; it gave the ability to make sure we had a level playing field and that no athlete had an obvious advantage over another by modifying the lasers in any way. If there were pistols outside the specifications, we pointed them out and adjustments were made.
‘During the final event at the London Games, the athletes had eight minutes preparation time before they compete where we make sure everything’s working, in that the shots are being registered on the targets. After this there is a 20 minute warm up period. During the warm up in the women’s final one of the athlete’s pistols stopped working. At this point, the coaches get agitated and everybody’s blaming everyone else. We quickly got the meter out; we did a test on the pistol and found that the power was way down and that the rechargeable battery was almost flat. We were able to prove this straight away. The athlete used the spare pistol and there was no problem. We were able to deal with that situation and everyone was happy. It meant we weren’t trying to guess. Before purchasing the calibrated laser power meters, to test the laser pistols, we would literally hold our hand out in front of the pistol and see if a red dot appeared. Now we had a bit of technology with which we could prove the performance of the pistol.
‘All the laser pistols and target manufacturers had previously been approved for use by the UIPM. When we did see some spikes in laser power, we didn’t allow the pistols to be used without adjustment. A nice progression for the future for laser pistol testing would be to include laser safety criteria in the test.’
The ADM1000 laser power and energy meter
Waveform displayed on a PC using the ADM1000 Interface software
Lasermet’s ADM1000 is a hand held, easy-to-use, high performance, laser power meter that has a sampling rate of 1MHz enabling the user to view and determine the power output of pulsed waveforms up to 400kHz in oscilloscope mode. It has super-fast response times down to 700 ns using the Lasermet Advanced Detector Interface. Users can measure peak or average power, or energy per pulse. Its’ calibration is traceable to International Standards. For further details please visit http://www.lasermet.com/laser-power-energy-meters.php