the way to calibrate a reciever-controller is the same way asa thermostat. monitor the branch line (output pressure to the controlled device) while monitoring your sensor input. A mixed air controller maintains the damper position to provide you with the temperature you set on the controller. take your temperature reading as close to the ma sensor as possible, now figure out your spring range (3-13, 3-8, 8-13 psi). set the reciever-controller at the temp your meter is reading and your branch line should read the middle of the spring range. if its 3-13, the mid point is 8. add the two numbers and divide by two ( ie 8-13 = 10.5). if the branch line does not equal the mid point of the spring range, find the calibration screw, slide bar, or whatever to make this so.
this way works well. use the same process for any type of control (pressure, temperature, humidity), just make sure you use the right measurements, and a GOOD, TRUSTY GAUGE. hope this helps