Containing some of the most stable (and expensive) foil resistors available, the M632 has just 1 ppm/°C temperature coefficient.
Decades can be used for AC application as well, see datasheet for typical frequency responses.
M6xx series was made to make resistance calibration as easy as it gets.
Large LCD shows all related parameters including total accuracy.
And there is no residual resistance or hidden absolute error so you don't have to calculate it by yourself, accuracy you see is what you get.
And that's not the only thing that firmware sorts out for you.
Would you like the resistance shown in temperature units? Distance? Force?
RTD and user function will do this for you.
Complete recalibration? Ten minutes and off you go.
All decades' functions can be remotely controlled via RS232, USB, LAN or GPIB interface.
This way you can introduce calibration/test stage directly into production line of any resistance based sensor and reduce time required for final quality tests dramatically.