Hioki MEMORY HiLOGGER LR8450 Instruction Manual page 27

Thermocouple wire break detection
• The system checks for wire breaks by applying a minuscule current each date refresh interval
when measuring temperature using thermocouples.
• Measured values are not affected since wire breaks are detected when measurement is not being
performed.
• If the data refresh intervals are the same, setting
noise rejection since it results in a cutoff frequency that is higher than the
Check "Digital filter" of each module in "10.2 Plug-in Module Specifications" (p. 2 43) for the cutoff
frequency.
• If the thermocouple resistance exceeds roughly the next value, the system will determine that a
wire break has occurred.
Thermocouple
K
J
E
T
N
R
S
B
C
When using a long thermocouple with
break detection.
Unit Measure
[Burn out]
Range
100°C f.s. 500°C f.s.
Ω
260
Ω
470
Ω
1530
Ω
220
Ω
520
Ω
50
Ω
50
–
Ω
220
[Burn out] set to [ON], use a thick-diameter wire to avoid false wire
Channel Trigger Alarm
Configuring Input Channels
to [ON] will result in less effective
[OFF]
2000°C f.s.
Ω Ω
5400 2940
Ω Ω
4150 200
Ω Ω
5970 9290
Ω Ω
5440 5440
Ω Ω
1470 590
Ω Ω
40 890
Ω Ω
80 1300
Ω
– 2090
Ω Ω
910 3090
Calculation System
1
setting.
23