A horizontal collimation test is performed on an automatic level following the prescribed standard procedure. With the instrument at point A, the reading of the rod at A was 1.870 meters and to B was 1.970 meters. After moving and leveling the instrument at B, the rod reading at B and A was found to be 1.850 and 1.770 respectively. What is the collimation error (measured in meters, up to two decimal places) of the instrument?