Michell Instruments S904, Руководство пользователя

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S904 & S904D User’s Manual
20 97209 Issue 3.1, October 2016
OPERATION
The following diagram shows how to connect three % RH probes using the 25-pin D-sub
connector on the rear panel of the S904D, and powering the probes using the internal
S904D power supply while logging their % RH and temperature outputs.
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POWER
U-CONTROLLER
CHANNEL 7
CHANNEL 8
CHANNEL 6
CHANNEL 5
CHANNEL 4
CHANNEL 3
CHANNEL 1
CHANNEL 2
25P. D-sub FEMALE
MEASURING CHAMBER
INTERNAL S904
25P. D-sub MALE
PCB S-576
25P. D-sub FEMALE
PCB S-676 Back Panel
PTC
RESERVED
(DO NOT USE)
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INPUT
OUTPUT
OUT-RH
OUT-T
GND
V+
OUT-RH
OUT-T
GND
V+
OUT-RH
OUT-T
GND
V+
Figure 22 S904D Wiring Diagram Example 2
S904D Data Acquisition Resolution
The data acquisition is made for 0 to 10 V input. The AD converter (analog to digital) is 12
bit data acquisition, so there are 4096 steps. If a device is connected with a 0 to 5 V output
the resolution goes down to 2048 steps and for an instrument with a 0 to 1 V output the
resolution goes down to 409 steps.
For example: If an instrument under calibration has an output of 0 to 1 V and the
temperature output range of the instrument is -40 to +60°C, (which is a total range of
100°C) then the resolution is 0.25°C. See the calculations below:
0 to 1 V
100°C
_____ = 0.25°C resolution which will be recorded in the data logger
409
0 to 5 V
100°C
_____ = 0.05°C resolution which will be recorded in the data logger
2048
0 to 10 V
100°C
_____ = 0.02°C resolution which will be recorded in the data logger
4096