Most people grumble about their electricity bills but almost no one considers that the meters might be providing an inaccurate reading. In the case of Hongkong Electric, every effort is made to ensure meter precision by the Meter Section, which puts every meter through a rigorous series of tests before installation. Tests carried out in the company's meter-testing workshop include an insulation test to ensure it is safe; a starting test to check the manufacturer's agreed current; and a no-load test to confirm the meter will not operate in a no-load situation. The last test is for accuracy. 'We use the British practice,' said Yuen Sui-see, chief engineer of the Transmission and Distribution Division. 'This allows a meter to operate with an accuracy of between +2.5 per cent and -3.5 per cent, although we try for a variation of +/-1.5 per cent.' Originally, testing was carried out on semi-automatic test benches, which required some manual input. But Yuen Wing-ying, senior meter engineer in the customer services department of the Transmission and Distribution Division, said the company was working on a fully computerised system due for completion by the middle of this year. 'It is actually ready now but we are introducing more refinements,' he said. Meters are generally replaced without any further testing after 10 or 20 years. Customers can arrange for a meter test. Last year, 35,926 single-phase and 5,494 three-phase meters were tested.