p.m., you would enter for “t” the number 150700 (for hour “15,” minute
“07,” and second “00”).
1
c. To verify this setting, ask for the current system time by commanding
TME [CR]
d. Now set your system’s internal date by commanding
DTE = d [CR]
where “d” is a number of up to 6 digits expressing the current date in
month, day, and year. For example, if today were June 9, 2001, you would
enter for “d” the number 60901 (for month “06,” day “09,” and year “01”).
2
e. To verify this setting, ask for the current system date by commanding
DTE [CR]
10
DATA CHANNEL CALIBRATION
The purpose of this section is to lead you step-by-step through a typical Sys-
tem 10 “real-channel” calibration. As explained in Section 1.G.2 of the
System
10 Guidebook
, a number of different calibration methods are available. The
method chosen for a given analog input channel will depend on the type of
source transducer, the characteristics of the transducer/cable/conditioner
combination, the extent of your knowledge of these characteristics, and the
possibility and/or convenience of producing actual or simulated transducer
inputs of known value.
TO FIND OUT WHICH CALIBRATION METHOD OR METHODS MAY BE USED
WITH A GIVEN CONDITIONER CARD, YOU SHOULD REFER TO THE RESPEC-
TIVE SUBSECTION OF
SYSTEM 10 GUIDEBOOK SECTION 1.E.2.
In very general terms, you will calibrate a signal-conditioner channel by com-
manding the system’s Central Processor to compute and store two constant
values: a
SCALING FACTOR (“m”) and a ZERO OFFSET (“b”). Automatically
and continuously applied to all subsequent readings of the given channel,
these two calibration constants define the linear proportionality expressed by
the equation “y = mx + b.”
3
In the following conventional “zero and span” tech-
nique, you will use the
ZERO (ZRO) and FORCE (FRC) commands to define
a channel’s “b” and “m” values, respectively. This is known as “Two-Point” or
“Deadweight” calibration.
a. In Section 8, above, you determined the CHANNEL NUMBER of the “live”
analog input channel you set up in Section 6. We will consistently refer to
this channel as “Channel No. x.” Thus, where “x” appears in the command
syntax below, you should enter the
actual Channel Number assigned to
B - 20
DATA CHANNEL CALIBRATION
“O
NTHE
A
IR
” (B-S
IZED
)
1
Though not entered in the TME command, separating colons will be shown in every dis-
play of TIME.
2
Though not entered in the DTE command, separating slashes will be shown in every dis-
play of DATE.
3
Where “y” is the measurement value reported for the channel and “x” is the ratio of the
actual voltage of the analog input signal to the positive full-scale voltage of the channel’s
chosen input “type.” As such, “x” is a unitless number operated upon by the “slope” coef-
ficient “m” and the offset term “b” to yield a true analog measurement. Both “m” and “b”
are expressed in the engineering units of the chosen input “type.”
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