For temperature measurements we are using a laboratory USB interface, the Novus myPClab, in conjunction with two PT100 sensors. This particular interface is specifically designed to work with temperature sensors and runs a linearization algorithm to increase the accuracy of our PT100 Class A sensors up to 0.2%. As we mentioned above, one PT100 sensor is installed at the top of the copper block. The other sensor is a long 10cm sensor which we install across the intake fan of the cooler.
A SL-5868P digital sound level meter with an USB interface is being used to monitor and record the sound level of the power supply under test. During our acoustics tests and in order to produce the most accurate results possible, all cooling fans of our PC temporarily cease to operate and only the cooler's fan(s) are being left operational. The sound level meter is mounted one meter away from the cooler in a straight line and with no obstacles in-between. Finally, a tachometer allows us to check the exact rotational speed of the fan at all times.
SL-5868P digital sound level meter