Thyracont VSR53D, Руководство по эксплуатации

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VSR-de-141106
4.5 Gas-Correction-Factors
Below 15 mbar the output signal of the VSR depends on type and composition of
the gas being measured. The unit is adjusted for N
2
and dry air. For other gases
the pressure display can be corrected below 0.1 mbar by setting correction
factors for the Pirani sensor via RS485.
The measurement results of the Pirani sensor is then individually multiplied with
the corresponding correction factor by the units microcontroller. The VSR can
thereby provide a corrected pressure signal as analog and digital output.
Correction factor 1 Pirani:
Ar
1,6 CO
2
0,89 He 1,0 Ne 1,4
CO 1,0 H
2
0,57 N
2
1,0 Kr 2,4
Address Code Data cks CR
Address:
3 Bytes, decimal; address space RS485: 001 – 999
Code: "C" for reading, "c" for writing a correction factor
Data: Query to read or unlock: 1 Byte; "1" for correction factor Pirani,
read or write: 6 Byte; unsigned int
cks: 1 Byte, checksum, defined as sum over all Bytes of the fields
address, code and data, modulo 64 plus 64.
CR: Carriage Return (0Dh, 13d)
The value in the data field when reading or writing correction factors contains
leading zeros and is equal to the 100fold of the factor. Range: "000020" for 0.20
to "000800" for 8.00
Example (for address-switch in position "1"):
Action Telegram to
transducer Answer telegram
from transducer
Read gas correction factor 1 "001C1E
C
R
" "001C000240z
C
R
"

c2=2.40
Unlock gas correction factor 1
Set gas correction factor 1
to 0.57 "001c1e
C
R
"
"001c000057`
C
R
"
"001c1e
C
R
"
"001c000057`
C
R
"
Please find further information about the Thyracont communication protocol in
chapter 4.2.