HP E1419A User Manual page 100

Custom EU Operation
NOTE
Custom EU Tables
Custom Thermocouple
EU Conversions
Custom Reference
Temperature EU
Conversions
Chapter 3
put in RAM, one copy into each channel's Table RAM Segment. The
conversion table-per-channel arrangement allows higher speed scanning
since the table is already loaded and ready to use when the channel is
scanned.
Custom EU conversion tables are loaded directly into a channel's Table
RAM Segment using the DIAG:CUST:LIN and DIAG:CUST:PIEC
commands. The DIAG:CUST:... commands can specify multiple channels.
To "link" custom conversions to their tables you would execute the
[SENSe:]FUNC:CUST <range>,(@<ch_list>) command. Unlike standard EU
conversions, the custom EU conversions are already linked to their channels
(tables loaded) before you execute the [SENSe:]FUNC:CUST command but
the command allows you to specify the A/D range for these channels.
The *RST command clears all channel Table RAM segments. Custom EU
conversion tables must be re-loaded using the DIAG:CUST:... commands.
The HP E1419A uses two types of EU conversion tables, linear and
piecewise. The linear table describes the transducer's response slope and
offset (y=mx+b). The piecewise conversion table gets its name because it is
actually an approximation of the transducer's response curve in the form of
512 linear segments whose end-points fall on the curve. Data points that fall
between the end-points are linearly interpolated. The built-in EU
conversions for thermistors, thermocouples, and RTDs use this type of table.
The HP E1419A can measure temperature using custom characterized
thermocouple wire of types E, J, K, N, R, S, and T. The custom EU table
generated for the individual batch of thermocouple wire is loaded to the
appropriate channels using the DIAG:CUST:PIEC command (see the
HP VEE example "eu_1419.vee"). Since thermocouple EU conversion
requires a "reference junction compensation" of the raw thermocouple
voltage, the custom EU table is linked to the channel(s) using the command
[SENSe:]FUNCtion:CUSTom:TCouple <type>[,<range>],(@<ch_list>).
The <type> parameter specifies the type of thermocouple wire so that the
correct built-in table will be used for reference junction compensation.
Reference junction compensation is based on the reference junction
temperature at the time the custom channel is measured. For more information
see Thermocouple Reference Temperature Compensation on page 3-64.
The HP E1419A can measure reference junction temperatures using custom
characterized RTDs and thermistors. The custom EU table generated for the
individually characterized transducer is loaded to the appropriate channel(s)
using the DIAG:CUST:PIEC command (see the HP VEE example
"eu_1419.vee"). Since the EU conversion from this custom EU table is to be
Programming the HP E1419A 99