MOST of the Government timetables for converting the United States to the metric system have 1980 as the deadline for schools, agencies and official functions to be conducted in metres, litres and kilos. But withjust two years remaining, Pro-metric forces are faced with a public resistance that is growing by leaps and bounds.

As in Britain, the true test of metric's acceptability in America will be in the schools. But for the first time, Washington officials in charge of the conversion are fretting that the test may be postponed, if not cancelled, by a rising tide of consumer protests.

Just how angry Americans really are about metrication was underscored by a recent Government survey that covered both large and small business and individual citizens as well.

The survey discovered that only half of the 500 largest U.S. companies have even begun conversion to metrication and less than 12 per cent of a 1,400 small business sampling have followed suit. More to the point, the survey revealed that U.S. citizens oppose the metric systern's use by two to one.

What has the pro-metrication forces in an uproar is that the Government survey (conducted by a Congressional accountancy office) accuses lhe Government of supporting metrication even though there is no convincing proof for either business or consumer of benefits to be derived. The report cites what it calls "the inevitability syndrome" - that is the belief that it is inevit able so one might as well join in and convert even though there are no benefits involved.

The report backs up the accusation by citing survey results that a mere 5 per cent of the 500 largest companiesin the US believe that metrication will significantly help their sales overseas

Given the consumer revolt, and business indifference, the accountancy agency recommended - to howls from the pro-metricationists elsewhere - that the Government should delay its timetable until a review is taken of whether the estimated billions of dollars involved in conversion are being wasted.

More to the point, a small band of anti-metrication Congressmen have announced that will reintroduce previously unsuccessful legislation to abolish the U.S. metric board (USMB) the agency in charge of pushing through conversion. The legislation would permit metrication where and when marketplace conditions warrant.

The first real public outcry came when the American wine,distilled spirits and soft-drink industries began the conversion to litre and millilitre bottles. The reduction in amount from pints and gallons was not accompanied by a reduction in price which brought allegations of cheating.

Similar attempts at packaging groceries, home appliance and paper products have met with similar resistance and suspicion to the point that most manufacturer of consumer goods have also included non- metric measurement on packages.

Earlier this year the Government's Highway authorities asked for public comment on the planned conversion of speed and distance signs and 98 per cent of the comments received were hostile. Pulblic opposition to the weather service's Celsius conversion was "almost unanimously against."

More to the point, America's multi-national corporations, which should be in the vanguard of conversion have with the exception of car mainufacturers and pharmaceutical companies, ignored metrication and aviation, petroleum, maritime, railway and construction industries have almost totally retained traditional measurements.

Even in, Detroit, most of the conversion progress is being carried out by General Motors with Ford not planning to convert until the late 1980s, and Chrysler and American Motors looking at the early 1990s.

As for the schools of America which are to produce a generation of children unable to calculate in quarts and feet, there is a problem as well. Despite pressure to convert, only 13 State governments have joined the national Government In the1980 conversion date and parental opposition in the remaining 37 states remains firm.

However one looks at it, the 1980 deadline for America's conversion to metrication does not appear reachable, perhaps never.