ALTANA Temp-Chart - Handbuch (Seite 88)

temp-gard Hardware temp-chart Software
11
Thermocouple Specifications
Over the years, ‘standard’ thermocouples have been developed using materials chosen for
sensitivity (voltage change per temperature change), linearity, (consistency of sensitivity
over the useful temperature range), price and availability. Current standards include types
K, N, R, S and T, each type being identified by the color of the connector. The ‘standard’
thermocouple probe for oven operation is the type K.
Type Temperature
Range
Cable Insulation Accuracy of probes supplied by
BYK-Gardner
K -150 to +1370 °C Glass Fiber, MI or
PTFE
(0 to +500 °C) ± 1,1 °C or ±0,4%,
whichever is greater
Thermocouple Insulation
The practical operating temperature of the thermocouple probes is limited by the
temperature characteristics of the cable insulation material.
Insulation Upper Temperature Limit
Glass Fiber, thick +500 °C (932 °F) continuous,
+700 °C (1292 °F) peak
Mineral Insulation (MI) +1250 °C
PTFE +260 °C
Glass Fiber insulated probes are impregnated with a silicone resin binder and suitable for
continuous operation at temperatures up to +500 °C (932 °F), and short term operation at
temperatures up to +700 °C (1292 °F).
PTFE (PTFE=Polytetrafluorethylene) is a robust, flexible, non-stick material suitable for
general purpose use at temperatures up to +260 °C (500 °F). It is the standard insulation
for temp-gard probes. It cannot be used when probe cables may be in close proximity to
heating elements.
Attention
PTFE is non-flammable. Temperatures greater than +260 °C will cause a thermal
decomposition of the product and release small amounts of toxic fumes. The most
important decomposition products are: