MULTICAL® 803
Kamstrup A/S · Technical description · 5512-2360_A1_GB_02.2019
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7.3
Offset adjustment of temperature sensor measurement
MULTICAL® 803 is available with possible offset adjustment of the temperature sensor measurement, thus
increasing the accuracy of the absolute temperature measurement. This is especially relevant in the installation
scenario in which the calculator is to be used for tariff billing based on absolute temperatures. In that case, it is an
EN 1434 requirement that the accuracy of the calculator’s absolute temperature reading must be within ± 1.0 K.
Offset adjustment is extremely relevant in district cooling installations too. In district cooling installations, the
customer often requires a maximum inlet temperature. Absolute temperature measurement with undesirable
inaccuracy can cause the supplier to supply water with a lower inlet temperature than promised, resulting in
unnecessary extra costs for the supplier.
The offset adjustment is not programmed at delivery of the calculator as the calculator is not supplied with mounted
temperature sensors. The offset must thus be programmed after delivery via the calculator’s SETUP loop (see
paragraph 6.3) or via METERTOOL HCW. See the technical description of METERTOOL HCW (5512-2097).
Note: Depending on the calculator’s configuration, the offset adjustment can be disabled and the menu item in the
SETUP loop will in that case display “OFF”.
If the temperature sensor pair of a calculator with offset adjustment is replaced, it is recommended to correct the
offset so that it matches the newly connected sensor pair. Alternatively, offset should be adjusted to 0.00 K, which
means that the function is switched off and does not contribute to an undesirable increase of the error of the
absolute temperature measurements.
The temperature sensor offset (t
r0
) can be adjusted in the interval -0.99…0.99 K according to the calculator’s
approval.
Note that the offset adjustment affects connected temperature sensors on both t1, t2, t3 and t4.
Due to this, it is recommended to disable the offset adjustment when the meter is installed with four
temperature sensors. The offset adjustment is intended for use with sensor pairs and 3-set sensors.
Note: The offset adjustment is only active on measured temperatures. If, for example, t3 has been selected
for a preset value, the offset adjustment will not influence the preset value.
Note that the required offset adjustment must be entered, not the error of the temperature sensor pair.
If the selected temperature sensor pair contributes with an error of -0.20 K, the meter’s offset must be set
to 0.20 K.