Calibration of the measured range is the most important work for global SLR network. Day to day calibration is performed normally by measuring the distance to one or more local ground targets whose distances from the instrumental reference point have been accurately measured by geodetic survey. System biases more than 2-3 cm can be detected by global analysis of standard target like LAGEOS. We set up a calibration instrumentation for SLR system except telescope, using collocation optics at Keystone Kashima station configuring all four connected to a single telescope and one of laser transmitting to the ground and satellite targets to receive simultaneous signal to demonstrate stability and difference of the ranges within millimeters. We also made diagnostics of the present SLR system using a portable SLR system which cover all the key electronics and local survey with accuracy of sub-centimeters. These are example of calibration method when full collocation is not available.