s 157 Right to enter under warrant.
(1) If the sheriff is satisfied— (a) that there are reasonable grounds for entering any land for any of the purposes mentioned in section 156(1) or (2), and (b) that— (i) admission to the land has been refused, or a refusal is reasonably apprehended, or (ii) the case is one of urgency, he may issue a warrant authorising any person duly authorised in writing to enter the land. (2) For the purposes of subsection (1)(b)(i) admission to land shall be regarded as having been refused if no reply is received to a request for admission within a reasonable period. (3) A warrant authorises entry on one occasion only and that entry must be— (a) within one month from the date of the issue of the warrant, and (b) at a reasonable hour, unless the case is one of urgency.