Enclosed Furnace Model Shown

24 KW Power Supply

The table below outlines the performance of each blackbody cavity in combination with a water-cooled 2KW power supply. The specifications are for the rated power supply and blackbody combination only. The HT-7000A controller and Exactus control pyrometer are needed to complete an automated control system. The range, repeatability and stability of the system are determined by the controller-pyrometer combination.

Dual Blackbody Type

Aperture Diameter
Inches (mm)

Useful Temperature
Ranges in Degrees C

a)-with 900nm Exactus™
b)-with 1600nm Exactus™

Time to Maximum Temperature
in Seconds


Gas Purge Flow Rate (Cu ft/hr)

Water Cooling
(US Gal/Minute)


5/8 inch

a) 500 - 3000
b) 300 - 2000

200 Seconds




1 inch

a) 500 - 3000
b) 300 - 2000

300 Seconds




1 inch

a) 500 - 3000
b) 300 - 2000

500 Seconds




2 inch

a) 500 - 2500
b) 300 - 2000

800 Seconds



Flat graphite plate, 1 " x 2", can be heated to 500 Watts/cm2 in 5 seconds, using flat plate attachment.
Operation above 2750 °C (5000° F) reduces operating life due to sublimation of graphite

Required Power: HT-9500 - 48KW, single phase AC 50/60 Hz. Standard voltage is 400/480 VAC. Custom voltage at no extra charge.

Enclosure: Powder coated, provides durable easy to clean surface.
   Dimensions: 28" wide, 40" long, 39" tall.

Options: Flat graphite plate, 1 " x 2", Optical Rail Bench, Custom stands for applications and alignment

Features and Notes

All models feature dual blackbody cavities with a 5:1 length to diameter ratio. Measured normal spectral emissivity at 0.65 microns is in excess of 0.995

The table shows the critical information for each combination of dual blackbody and the 24 KW power supply. To choose the correct combination for your application follows the steps below.

  1. Determine the maximum temperature that you must perform calibrations. The maximum temperature is listed in the Useful Range column of the tables.
  2. Determine the minimum aperture that is required for all instruments you intend to calibrate. It is best to choose the smallest dual blackbody size that will meet your needs. The electric power, water cooling, and purge gas requirements are less for smaller blackbodies.
  3. Ask the question: Will we need a larger aperture or higher temperature in the future? Since different rated power supplies are available one can upgrade to a larger aperture at higher temperatures if you have a large enough power supply. Purchasing a HT-5500 with 15 KW power supply will allow you to achieve maximum performance from all blackbody sizes if you expect to upgrade in the future.
  4. Exactus™ pyrometer summary specifications:
    • Accuracy ± 0.2% of temperature
    • Repeatability ± 0.5 °C
    • Resolution 0.05 °C (Decreasing near low end of temperature range
Copyright 2003 Thermo Gauge Instruments, Inc. , All rights reserved..... Exactus™ is a Trademark of Englehard Corporation