shí yàn shì / lǐ / bì xū / píng bì / diàn cí zào shēng / fǒu zé / cè liáng / jié guǒ / bù zhǔn实验室里必须屏蔽电磁噪声,否则测量结果不准。The laboratory must shield electromagnetic noise, otherwise the measurement results will be inaccurate.