Payments from the funds provided for by this chapter shall be made by the comptroller upon a warrant signed by the chairperson and countersigned by the executive director of the retirement system. No warrant shall be drawn except by order of such board duly entered in the record of its proceedings. The chairperson may by duly written authority and during a period of time not extending beyond three months, and specified in such authority, designate and authorize his or her secretary or any accountant or clerk in the employment of such board to sign in his or her name warrants drawn upon the funds provided for by this chapter. Such written authority shall be duly filed in and remain of record in the office of the comptroller and in the office of the executive director of the retirement system.