तस्यादित उदात्तमर्धह्रस्वम्

Of it (स्वरित-s) the first portion is उदात्त , to the extent of a half measure, or prosodial length.
It has been defined that svarita accent is a combination of udatta and anudatta. It remained doubtful what portion was acute and what grave. The present sutra clears up the difficulty, by declaring that in svarita, the first half is accute and the other grave.

The phrase ardhahrasva is used to indicate half the measure of a short vowel. Thus if a short vowel is svarita, its matra being one, half will be udatta and the other half anudatta. If a long vowel, whose matras are two, be svarita then 1/2 will be udatta, 1 1/2 will be anudatta. If a pluta (protracted) vowel be svarita, then first half measure will be udatta, and the remaining 2 1/2measures will be anudatta. In short, the udatta portion of a svarita must not occupy more time than is taken in pronouncing a half short vowel. Thus in शि॒क्य॑म् sikyam, the a is svarita, half being acute, the other half grave or monotony; in क॒न्या॑ kanya, the long a is svarita, its first half measure is acute, the remaining 1 1/2 is grave; in मानवका॑३ manavaka, here a prolated is svarita, its first 1/2 is acute, the balance 2 1/2 measure is grave.