The purpose of the flame in flame atomic-absorption spectroscopy is to（）

A:Purify the sample B:Desolvate and atomize the analyte atoms in a sample C:Excite the analyte atoms D:Ionize the analyte atoms

Flame Detail指的是（）。

A:火焰的大小 B:火焰精细度 C:火焰的高度 D:火焰的样本数

A steady flame in a gas burner is the result of ______.

A:a burning velocity equal to the combustion wave B:fuel being supplied at the same rate as the combustion wave C:fuel being supplied at a higher rate than that of the burning velocity D:a low combustion wave

When there is a flame failure in an automatically fired auxiliary boiler, the _____.

A:air supply is shut off B:fuel supply is shut off C:water supply is shut off D:safety valve lifts

The color of the flame on a halide torch without any refrigerant present is _____.

A:blue B:green C:orange D:purple

Failure of the burner flame in an auxiliary boiler would probably be a result of .

A:water in the fuel oil B:broken high tension leads C:incorrect electrode setting D:full fuel pressure at the nozzle

In the event of a flame failure in an auxiliary water-tube boiler, you must______.

A:relight the boiler immediately to prevent loss of steam pressure B:relight the fire off the brickwork as the bricks are cherry red C:purge the furnace of any combustible gases before attempting to relight the fire D:speed up the feed pump to prevent dry firing when the burner flame is reestablished

A smoking burner with a pulsating flame in auxiliary boiler, is an indication that the .

A:fuel oil supply temperature is normal B:burner electrode is incorrectly positioned C:fuel ／air ratio is incorrect D:ignition current is too low

In general, the oil mist detectors include a built-in heating unit and a compact plug for electrical connectionThe function of heating unit is to ____.

A:avoid false alarms as a result of condensing water vapor B:avoid danger of frost under very cold weather C:reduce the viscosity of the crankcase atmosphere in order to improve the fluidity D:keep the temperature of the oil mist detectors in an appropriate range

What type of fire detectors is the first to go of in case of a fire?

A:Smoke detectors B:Flame detectors C:Heat detectors D:Gas detectors"