2000I & 2000M Instrument’s User Guide, Revision B
54
Where
EZ
IN
is the tolerance of the input impedance
(in ppm, 1% = 10000ppm).
Where
Error
is
the increase in the limits of error (in ppm).
Thus, if the combined input impedance is 1M
• 0.1%, at an output level of
l00mV the increased uncertainty is an insignificant: 0.09ppm, and the correction
is 1.00004505—an increase in the output level requested of 45.05ppm.
Setting Scale and Offset Factors for Computed Output Mode:
The equation used by the 2000 instruments to compute the output level from en-
tered data while operating in this mode, is:
Output level (scale factor * entered data) + offset factor
The instruments automatically calculate scale factor and offset factor from the
data at points A and B as follows:
Scale factor (outputB - outputA ) / (userB - userA)
Offset factor = outputB - (scale factor * userA)
The 2000 instruments simulate a 4 - 20mA loop whose output corresponds to a
pressure span of 50 to 150psi:
outputA = 4mA
userA
= 50psi
outputB = 20mA
userB
= 150psi
After entering this data (selecting “Calculated Output”
mode), enter data in the
units of psi, the 2000 instrument will then output the corresponding current (e.g.,
for an entry of 100psi, the output is 12mA). Note that any Units/Enter keys (V, A,
ºC or ºF
)
may be used to enter data while in this mode.
The 2000 instruments can be operated in parallel with a sending unit of a trans-
ducer having the above characteristics. Use the instrument to modify the trans-
ducer indication by entering the data entry as given above, except with the 4mA
offsets removed. Thus output
A
and output
B
will be 0mA and 16mA respectively,
and user
A
and user
B
will be 0psi and 100psi respectively. The instruments output
Summary of Contents for Xitron 2000 Series
Page 1: ...USER GUIDE 2000 Family DC Temperature Source Instruments...
Page 2: ......
Page 18: ...2000I 2000M Instrument s User Guide Revision B 18...
Page 42: ...2000I 2000M Instrument s User Guide Revision B 42...
Page 47: ...Using the Memory Options 47...
Page 60: ...2000I 2000M Instrument s User Guide Revision B 60...
Page 91: ......
Page 92: ...2000I 2000M Instrument s User Guide Revision B 92...
Page 95: ...Appendix B General Specifications 95...
Page 97: ...Password Page 97...
