Hioki LR8431, Instruction Manual

Page: 60 / 204

3.4 Setting Configuration 2 – Input Channel Settings
52
[

C]
1000
400
0
-200
-1000
If Thermocouple Measurement Range is Exceeded
Example: Using a type T thermocouple with range -200 to +400°C
When measurements are outside of the range of the thermocou-
ple, the waveform saturates and clings to the top of the screen as
shown at the right.
The numerical measurement values are displayed as “OVER” and
the cursor measurement value, calculation values and saved data
are handled as full-scale output values of the 16-bit A/D converter.
See: "LR8431-20 Measurement Values" (p. A12)
About Burn Out Detection
Broken (disconnected) thermocouple wires are detected using a tiny (300 nA) sensing
current. The thermal equivalent of the thermoelectromotive force (thermocouple resis-
tance (

) times the 300 nA sensing current) is added to the measured value. However,
measurement errors can occur if the thermocouple wire is long or if the wire itself has a
large resistance, in which cases broken wire detection should be disabled (set to Off).