What Does the Heat Spy Measure?
Temperature at a Distance
You can stand 1 to 40 feet away and conveniently measure temperature of bearings, kiln and furnace walls, locate hot spots in reactor shells, steam piping, and insulation surfaces. Specialty models can be used up to 300 feet away from your temperature target.
Temperature of Moving Material
Moving materials require two Heat Spy features not available by any other measurement method: non-contact with the process material, and fast measurement of rapidly moving materials. Measure continuously moving solid materials such as plastic film and extrusions, pulp and paper, textiles, rubber, steel sheet, coating, or paint.
Temperature of Small Low Mass Materials
Electronic components or other small or low mass items can be measured with a Heat Spy where a contact thermometer would change the measured condition through heat transfer.
Temperature of Areas Too Hot to Approach Safely
In foundries, forging shops, glass factories, and power plants, Heat Spy’s can allow you to stand away from heat or high voltage to measure temperature up to 5800°F (3200°C).
Temperature of Rough Surfaces
The Heat Spy does not require contact with the target. It measures rough and uneven surfaces and averages temperature readings of the observed target area. It affords users an efficient method of measuring the temperature of granular materials, rough castings, and forgings.
Temperature Requiring Quick Measurement
Opening and closing of injection molding dies requires temperature to be measured in less than 2 seconds. The Heat Spy is ideal for use with rotating machinery - large motor armatures and drive couplings for example.
Heat Spy Emissivity
Emissivity in Infrared measurement refers to the ability of the measured surface to emit radiation. Surfaces vary in emissivity and this must be taken into account before accurate readings can be obtained. The emissivity ratio represents the amount of radiated energy the measured surface allows to be returned to the instrument. A return of 100% of the energy is measured as 1.0 emissivity. If all the radiated energy is reflected and/or transmitted and none emitted, the emissivity ratio is 0.0.
A perfect radiator, such as a black body, has a 1.0 emissivity ratio and a very shiny or highly polished surface has a ratio of 0.2 or lower. Most textured or painted surfaces have an emissivity ratio of around 0.95. Many Heat Spy thermometers feature adjustable emissivity from 0.10 to 1.00. Other Heat Spy’s without adjustment are set at 0.95 and include instructions on how to adjust readings to take low emissivity into account.
Sighting with the Heat Spy
Understanding the relationship of target size to spot size is critical to obtaining accurate temperature readings with any infrared thermometer. Target size is the size of the object whose temperature you are measuring. Spot size is an indication of the diameter of the measurement area of the instrument. Picture a flashlight; as you shine it on a wall, the size of the bright spot on the wall gets larger as you move away from the wall. The same is true of the spot size for an infrared thermometer. For accurate temperature measurment, the spot size should always be smaller that the target size, since the instrument will “average” the temperatures of everything inside the spot. The spot size is expressed as a fraction of the distance to the target. For example a 10:1 instrument has a spot size of 1 foot at 10 feet from the target.
The distance to spot size ratio is specified for all Heat Spy models