An example measurement with a 1051,9 Ohm resistor that gave a readout (for PT1000) of 13,3°C.
So the accuracy in my case - using the 4 kOhm range - is:
0,015 % of readout (1051,9 Ohm conforms to 13,3°C)
PLUS
0,002 % of range (which is 4 kOhm)
PLUS
(as 13°C is already outside the specified temp range of 18 - 28°C and we suppose the instrument to be in same temperature condition as the sensor is)
5 * 0,002 % of readout
PLUS
5 * 0,0002 % of range
0,015 Ohm + 0,08 Ohm + 0,011 Ohm + 0,04 Ohm = 0,146 Ohm of uncertainty
which means that your measurand at the HMC8012 is somewhere between 1051,754 (13,3 °C) and 1052,046 Ohm (.13,3 °C).
This is better than the tolerance of the PT1000 class B which is +/- 1,428 Ohm or +/- 0,37°C.
We recommend to perform the measurement in 4 wire mode for best results.