There shall be set aside by the board of county commissioners of each county upon the request of the sheriff thereof by order entered in their minutes a sum not exceeding ten thousand dollars ($10,000), to be known as the "Sheriff’s Revolving Expense Fund," in this chapter referred to as the fund, out of which fund any warrants drawn under the provision of this chapter shall be paid. The amount set aside for such fund shall be charged by the auditor against the sheriff and the board of county commissioners may require of the sheriff, a bond, in addition to his official bond, in such sum as the board may determine, to secure the repayment of such sum or sums withdrawn. The fund so set aside shall remain in the county treasury subject to withdrawal and reimbursement as herein provided.