10 The Interface Solution Experts
Programmable Isolated
Thermocouple Transmitter
TIY
The configuration jumpers set the following features:
J301
– Reference Junction Compensation (RJC)
Stored – RJC Activated
Installed – RJC Inactive
This jumper is valid for thermocouple
inputs.
When J301 is installed (No
RJC), the TIY assumes the reference junction to
be at zero degrees Celsius (32°F), and allows
standard ranging to be accomplished using a
millivolt input source and copper wire instead of
thermocouple wire.
J302
– Displayed Temperature Type
Stored – Temperature displayed in Fahrenheit
Installed – Temperature displayed in Celsius
If a millivolt range is selected with the Range
Jumpers, the LCD displays millivolts and this
jumper has no effect
J303
– Burnout
Stored – Upscale Burnout
Installed – Downscale Burnout
This jumper determines the reaction of the TIY
output when an error is detected or when the
input is open. The output will normally follow the
burnout jumper setting.
J304
– Linearization
Stored – Linearization
Installed – No Linearization
This jumper is valid for thermocouple inputs
ONLY. When J304 is installed (no linearization),
the output is linear with input millivolts, not
temperature, and the LCD readings are no
longer valid.
J305
– Ranging Method (Calibration)
Stored – Standard Ranging
Installed – Quick Ranging
Standard Ranging requires an input source, an
output monitoring device, and power to perform
ranging. The push buttons are used to capture
the zero and span inputs and trim the zero and
full-scale outputs.
Quick Ranging can only be performed on units with
LCDs. To set the 4-20 mA output with this ranging
method, only power is needed for the unit. The push
buttons are used to enter values for zero and span
(full-scale).
Note
:
Any time a jumper is changed while power
is applied, one of the four push buttons
must be pressed for the TIY to acknowledge
the configuration change.
Calculating the TIY’s Accuracy
The output accuracy of the TIY is ±0.05% of span.
Accuracy improves for wider spans, and degrades for
narrower spans.
Table 5 shows selected narrow, medium, and wide
spans for each programmed input code (by thermo-
couple type). At the top of each column is the accu-
racy rating for the spans listed in that column.
The accuracy formula shown below is used for cal-
culating the total error for a TIY programmed for the
J1 input code (see Table 1) with a wide input span of
300°C (see Table 5).
EXAMPLE:
Input Ac (Span x Output Accuracy) + Cold
Junction Compensation Accuracy = Total Error (in
degrees)
±0.08°C + ±(300°C x 0.05%)°C + ±0.25°C = ±0.48°C
