Fig. 8 Chart: Rtd Measuring Range; Fig. 9 Concatenation Of The Uncertainties In Rtd Measurement - Beckhoff EPP3504-0023 Short Manual

3
) Values related to a common mode interference between SGND and internal ground.
RTD measuring range
Fig. 8: Chart: RTD measuring range
In temperature mode, only the legacy range is available, the extended range is not available.
The temperature display in [°C/digit] (e.g. 0.1°/digit or 0.01°/digit) is independent from the electrical
measurement. It is "just" a display setting and results from the PDO setting, see chapter "Comissioning".
Data for the sensor types in the following table
The values for the sensor types listed in the following table are shown here merely for informative
purposes as an orientation aid. All data are given without guarantee and must be cross-checked
against the data sheet for the respective sensor employed.
The RTD measurement consists of a chain of measuring and computing elements that affect the attainable
measurement deviation:
Fig. 9: Concatenation of the uncertainties in RTD measurement
The given resistance specification is decisive for the attainable temperature measurement accuracy. It is
applied to the possible RTD types in the following.
On account of
• the non-linearity existing in the RTD and thus the high dependency of the specification data on the
sensor temperature T
• the influence of the ambient temperature on the analog input device employed (leads to a change in
T on account of ∆T
measured
no detailed temperature specification table is given in the following, but
• a short table specifying the electrical measuring range and orientation value for the basic accuracy
• a graph of the basic accuracy over T
attainable basic accuracy is implied on account of the actual existing ambient temperature)
• equations for calculating further parameters (offset/gain/non-linearity/repeatability/noise) if necessary
from the resistance specification at the desired operating point
RTD types supported by the EPP3504-0023:
EPP3504-0023
and
sens
although T = constant)
ambient sens
(this at two example ambient temperatures so that the
sens
Version: 1.2
Product overview
27