Each insert is drilled with bores of different sizes to match for calibration of varying-sized temperature sensors or transducers.
The temperature sensor bores in the dry block are tight enough to enable low thermal resistance between the sensor and the insert provided.
If the bores provided are too loose then the sensor gets stabilized slowly, but sometimes they are unable to reach the insert temperature due to stem conditions.
Generally, when we insert a temperature sensor or transducer to be calibrated in a dry block, the temperature sensor is the principal component to calibrate a temperature loop.
All dry block temperature calibrators have routes to
Sourcing Temperature
Reading, Analyzing, & Reporting the Temperature.
Sourcing Temperature
Two common methods of sourcing temperature calibrators include
A. Simulation
Temperature calibrators using simulation hand-held devices.
Its internal electronic circuitry produces
Different voltage levels are usually in terms of millivolts.
Resistance to simulate temperature sensors.
An output voltage signal generated represents a thermocouple unit.
An output resistance signal represents RTD, Thermistor, or PRT.
A simulator verifies sensor readouts such as for temperature transmitters or oven displays.
This simulator measures and displays temperature sensors’ electrical output correctly.
The simulator allows the user to select a temperature sensor type to simulate during operation.
B. Physical Heat Generation
Temperature calibrator generates physical heat including
Dry-Block Furnaces,
Infrared Radiation (Ir) Calibrators,
Temperature Chambers,
Ovens & Temperature Calibration Baths.
This calibrator consists of built-in sensors for measuring and displaying the calibrator temperature.
These are considered and used as reference sensors then built-in sensors having low accuracy.
It is required to insert sensors having high accuracy called external reference probes such as Platinum Resistance Thermometers, or Resistance Temperature Devices to obtain more accuracy and low uncertainty.
These are inserted into the heat source along with the device under test (DUT).
Reading, Analyzing & Reporting Temperature
There are some common methods by that a temperature calibrator can read, analyze and report temperatures.
The common way for the device to source the temperature must have an input to measure the DUT sensor.
This Dry block temperature calibrator displays the temperature of the dry block and Device under test.
Another common method is inserting a sensor into the calibrator, and the sensor stays connected to the display, & transmitter.
This method displays both temperatures of the calibrator & DUT.
This method is recommended, & considered as best because it compares and verifies both temperature of the calibrator, & the DUT sensor.
Some temperature calibrators are built with an interface unit for the user to link a reference digital thermometer system to determine the highest accuracy
Features of Dry Well Calibrator
Temperature ranges from -40℃ to 2200℃
It has a Portable design & rugged structure.
Accuracy is good
Rapid to-temperature climatic science performance in their stability
Dual-zone control.
For reference Thermometer, RTDs, and T/Cs dry block calibrator provides a multi-channel readout for use.
The dry block calibrator provides task documentation, switch testing, and HART communication.
Touch screen with Color Display interface.
Provides an option to choose your own range.
Set point control by reference PRT
Self-calibration feature
Parts of the Dry Block Calibrator
The dry Block Calibrator consists of
A well-designed insert hole for lodging various devices under test or sensors to be calibrated.
Heating coils for the escalating temperature to the required value.
Reference thermometer fixed internally within dry block calibrator to determine and display device temperature.
An electronic PID controller is required to provide a temperature Setpoint and to control the temperature of the Dry Block calibrator.
Specification of Dry Block Temperature Calibrator
Range
300°C to 1200°C
Resolution
1°C
Accuracy
±2°C
Stability
±0.5°C
Stabilization Time
15 Minutes
Temperature Readout
°C / °F Selectable
Well Diameter
26 mm
Immersion Depth
105 mm
Dry Block Material
Inconel
Heating period
60 Minutes approx.
Cooling Time (to min.)
45 Minutes approx. (with Forced Air Cooling)
Switch Test facility
Provided
Thermowell Diameter
8 mm
Housing / Mounting
Bench-top
Power Supply
230V AC, 50 Hz
Instrument Dimensions
160 x 365 x 450 mm (L x D x H)
Instrument Weight
15 Kg.
Measuring Capacity
Thermocouples J, K, R, S, N, B, T
RTD
Pt100 IEC Std.
mA
0 to 25 mA
mV
0 to 100 / 1000 mV
Volt
0 to 10 V
Resistance
0 to 500Ω / 3.5 KΩ
What are the other names of a Dry Block temperature Calibrator?
Commonly these are called by
Dry Block
Dry Block Temperature Calibrator
Dry-Well Calibrator
Block Calibrator
Temperature Block
Dry Bath Temperature Calibrator
Advantages of a Dry Block Calibrator
Dry block calibrators are easy to carry out in the field.
It does not contain any hot fluid that may spill during carrying.
These devices do not contaminate the calibrating temperate sensors.
Disadvantages of a Dry Block Calibrator
Accuracy is less.
Compared to a liquid bath it offers less stability.
Calibration is difficult for sensors having short stems and oddly shaped ones.
Not applicable for liquid use.
Requires some heat transfer fluids or pastes in rare cases.
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Please send heat treatment furnace calibration procedures