Isotech 944 Specifications

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CALIBRATION SOLUTIONS

Surface Measurement

30 to 350°C

g

Indicates True Surface Temperature

g

30°C to 350°C

g

Resolution 0.1°C

The fundamental problem with surface temperature
measurement is that it is subject to large stem conduction
errors, also because heat conducted from the surface of
the hot-plate causes a localised cold spot to be created
which means that the temperature indicated by the hot
plate is not necessarily the temperature at the point of
measurement.

An ideal system would not disturb the heat-flux from the
hot-plate.

During 1993 such a system was described (ref. “Progress
in Contact Thermometry” 1993 B. D. Foulis) and Isotech
have the inventors permission to make and market the
device World-wide.

Model 944

Principal of Operation

A fine wire type N thermocouple is used as the surface
temperature sensor, a second junction 2 to 3mm along
the thermocouple, senses the temperature difference due
to heat flux along the sensor.

A heater heats the thermocouple stem until the temperature
gradient is zero, thus creating a measurement without
stem conduction, or disturbance of the hot-plate’s surface.

The 944 can be used with the Isotech Small Hot Plate
model 983. A traceable calibration certificate is available
to order.

Model 944 True Surface Temperature

Measurement System

Temperature Range 30°C to 350°C

Resolution 0.1°C or 0.1°F
of display

Stability ±1°C

Accuracy ±2°C with TRACEABLE Certification

±5°C without Certification

Probe Assembly Probe Diameter 7.5mm

Probe Length 150mm
Lead Length 850mm

Power Supply 100V - 120V, 50 / 60Hz or

200V - 240V, 50 / 60Hz

Dimensions Height 90mm

Width 153mm
Depth 265mm (excluding plugs)

Weight 4kg

How to Order

Model 944 & Probe 935-14-81
Please state supply voltage required
Please state if Calibration is required