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14. THERMOCOUPLE INPUT
The thermocouple signal conditioner board used for temperature measurement can be confi-
gured via jumpers for either type J, K, E, N thermocouples or type T, R, S thermocouples, and
for upscale or downscale open sensor indication. The meter software recognizes the thermo-
couple board and will bring up the appropriate menu items for it; however, it does not recognize
jumper settings.
For each jumper selection, the thermocouple type, display in °C or °F, and resolution of 1°, 0.1°
or 0.01° are user program selectable. High resolution should only be used for relative readings,
not absolute readings. Although available, 0.01° resolution is not recommended for thermo-
couples. Offset adjustment is available for thermocouples and is normally set to 0000.0. If °C is
selected, entering an offset of 0273.2 will change the display to Kelvin. If °F is selected, entering
an offset of 0459.7 will change the display to Rankin.
The addition of a relay output board turns the thermocouple meter from a temperature indicator
into an on/off temperature controller. Please see further manual sections for
, and
..
BOARD SETUP VIA JUMPERS
1.
Jumpers are installed on pins bridging letters.
2.
Use 2.5 mm (0.1") jumpers.
3.
Store spare jumpers on an unused jumper post.
THERMOCOUPLE READING ERRORS
The following types of thermocouple errors need to be combined:
1. Conformity error.
The difference between the meter reading and the temperature stated
in NIST Monograph 125 (IPTS-68) for a specified thermocouple type, the thermoelectric
voltage in mV, and a cold junction reference temperature of 0°C. For our meters, this error
is typically less than 0.2°C across the entire thermocouple range.
2. Voltage measurement error at 25°C.
With our meters, this is less than 0.01% of full
scale at a meter temperature of 25°C, and hence also less than 0.01% of the temperature
reading. This error is negligible.
3. Voltage measurement span tempco error.
With our meters, this error is less than
±0.003% of the voltage reading/°C as the temperature of the meter changes, and hence
also less than ±0.003% of the temperature reading/°C. This error is negligible.
Type
E4 Jumper
J, K, E, N,
T, R, S
none
j
Open Indication
E3 Jumper
Upscale
Downscale
h
i
h
i
j
E4
E3
3
4
1
2
PNP transistor
J5-X
J5-Y
c + b
e
- Sig
+ Sig
