Campbell Scientific CR200/CR200X-series Dataloggers - Manual (Page 51)

Section 4. Sensor Support
Note The accuracy specification includes only the CR200(X)’s contribution to
measurement error. It does not include the error of sensors.
For example, assume the following (see Specifications (p. 35)):
• Input Voltage: +2000 mV
• Programmed Measurement Instruction: VoltSE ()
• CR200(X) Temperature: Between -40°C and +50°C
Accuracy of the measurement is calculated as follows:
Error = Gain Error + Offset Error,
where
Gain Error = ± (2000 * 0.0025)
= ±5 mV
and
Offset Error = 1.2mV
Therefore,
Error = Gain Error + Offset Error
= ±5 mV + 1.2 mV.
= ±6.2 mV
A worst case accuracy in these conditions is
Error = ±(2000 mV * 0.01 + 2.4 mV) = ±22.4 mV
In contrast, the error for a 500 mV input under the same constraints is ±2.45 mV
typical and ±7.4 mV worst case.
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