तस्यापिहितकाचकस्योदके निमज्जत एकदेशः सीदति पटलान्तरेषु वा सूच्या भिद्यते ॥ ॥
tasyāpihitakācakasya udake nimajjata ekadeśaḥ sīdati paṭalāntareṣu vā sūcyā bhidyate
Para ese objeto sellado con una cubierta de vidrio: al sumergirlo en agua, una parte se hunde; o bien, entre las capas se perfora con una aguja (para probarlo).
They are quick, low-cost, and reproducible—ideal for routine enforcement by inspectors without specialized equipment.