Campbell CR800 Series, Руководство оператора

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Section 5. Overview
65
This section discusses direct sensor-to-datalogger connections and applicable
CRBasic programming to instruct the CR800 how to make, process, and store the
measurements. The CR800 wiring panel has terminals for the following
measurement inputs:
5.2.1 Time Keeping — Overview
Related Topics:
• Time Keeping — Overview
(p. 65)
•
Time Keeping — Details
(p. 311)
Measurement of time is an essential function of the CR800. Time measurement
with the on-board clock enables the CR800 to attach time stamps to data, measure
the interval between events, and time the initiation of control functions.
5.2.2 Analog Measurements — Overview
Related Topics:
•
Analog Measurements — Overview
(p. 65)
• Analog Measurements — Details
(p. 313)
Analog sensors output a continuous voltage or current signal that varies with the
phenomena measured. Sensors compatible with the CR800 output a voltage.
The CR800 can also measure analog current output when the current is converted
to voltage by using a resistive shunt.
Sensor connection is to H / L terminals configured for differential ( DIFF ) or
single-ended ( SE ) inputs. For example, differential channel 1 is comprised of
terminals 1H and 1L , with 1H as high and 1L as low.
5.2.2.1 Voltage Measurements — Overview
Related Topics:
• Voltage Measurements — Specifications
• Voltage Measurements — Overview
(p. 65)
• Voltage Measurements — Details
(p. 345)
•
Maximum input voltage range:
±
5000 mV
•
Measurement resolution range: 0.67 µV to 1333 µV
Single-ended and differential connections are illustrated in the figures Analog
Sensor Wired to Single-Ended Channel #1
(p. 66)
and Analog Sensor Wired to
Differential Channel #1
(p. 67).
Table Differential and Single-Ended Input
Terminals
(p. 67)
lists CR800 analog input channel terminal assignments.
Conceptually, analog voltage sensors output two signals: high and low. For
example, a sensor that outputs 1000 mV on the high lead and 0 mV on the low has
an overall output of 1000 mV. A sensor that outputs 2000 mV on the high lead
and 1000 mV on the low also has an overall output of 1000 mV. Sometimes, the