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Instruction for use | Supercal 5
11.8.2 Permissible Errors and Limit Values
With permanently connected temperature sensors, the maximum permissible error (in %) is
calculated according to the equation:
Et
= ± ( 0,5 + 3 Δөmin/Δө )
Δөmin = permissible minimum temperature difference = 3 K
(according to MID EC type-examination certificate)
With permanently connected temperature sensors, the screws of the connection terminals
are secured with an adhesive seal. A subsequent exchange of the temperature sensors is
therefore not possible without damaging the seal.
The software of the calculator checks whether the measured temperatures are within the
permissible measuring range.
If this measuring range is exceeded, the calculator indicates a measuring error.
11.9 Energy Measurement
11.9.1 Error limits
A heat flow can be determined from the knowledge of its mass, its specific heat capacity and
the temperature difference.
Here the difference of the enthalpy between the “temperature high” and the “temperature
low” duing a given time t is integrated. The equation for calculation of thermal energy ac-
cording to EN 1434-1, point 8, is used here.
The permissible error is calculated retroactively:
Ec = ± ( 0.5 + Δөmin/Δө )
The minimum temperature difference Δөmin depends on the assembly of the subassemblies.
If the calculator and temperature sensor are tested as a unit, it is 2 K according to PTB ap-
proval and 3 K according to MID approval.
No approvals below 3 K are provided for the EC type-examination certificate.
11.9.2 Cooling Energy
If a heat meter is used to measure the cooling energy in the return flow, the “temperature
sensor low” is installed in the flow and the “temperature sensor high” in the return flow.
The Supercal 5 I are generally tested ex works in accordance with the metrological measur-
ing points of EN1434 (2006) for refrigeration and heat energy.
11.9.3 Refrigeration Energy – Combined Cold/Heat Meter
A calculation of the cooling energy for the combined cold/heat meter (tariff function cold/
heat tariff) takes place if the following two conditions are fulfilled simultaneously:
Temperature difference (Δt) < – 0,2 K
“Cold pipe Temperature” < 18°C
The threshold value of 18°C for switching over the combined cold/heat meter is parameter-
ised ex works. A change by means of software SuperProg via the optical interface is possible.
If the calculator is used for combined heat and cooling measurement, cooling capacity and
temperature difference are displayed with a minus (-) and the corresponding values are
assigned to tariff 1.
For the measurement of cold energy, an officially certified calibration can only take place
if the cold energy is determined within the permitted temperature range with the medium
water (without glycol).
