Pyrometers and Infrared Thermometers
IR Thermometer measures asphalt production temperatures.
Press Release Summary:
Stand-alone RT8A, offered in 4 models that cover temperatures from 0-1,000°F, can be integrated directly into 2-wire, 4-20 mA current loop with indicators, controllers, and recorders for measuring, monitoring, or control purposes. Along with NEMA 4X housing and optional cooling and lens purging facilities, product features adjustable response time from 1-10 sec and accuracy within 0.5% of span. Thermometer also helps minimize energy expenditure.
Original Press Release:
The Latest in Measuring Asphalt Production Temperatures
The new rugged RT8A infrared thermometer from Land Instruments International is the company's latest product for monitoring asphalt temperature throughout the production process to ensure product quality and minimise energy costs.
The outcome of over 25 years' experience of the asphalt industry, the stand-alone RT8A range of infrared thermometers encompasses four models covering temperatures from 0 to 500°C/0 to 1000°F.
A comprehensive choice of mounting and protection accessories from the well-proven System 4 range makes it easy to install the thermometer at the optimum point in the process.
RT8A can then be integrated directly into a simple two-wire 4 to 20mA current loop with low cost indicators, controllers and recorders for measuring, monitoring or control purposes.
The protection afforded by the robust, IP65/NEMA 4X rated housing can be supplemented by optional cooling and lens purging facilities when required.
Accurate, reliable and stable temperature measurement is assured by the RT8A thermometer's response time, which is adjustable from 1 to 10s; accuracy within <0.5% of span; and minimal drift with change in ambient temperature of less than or equal to 1.5°C per 10°C.
At all points of the manufacturing process, the RT8A infrared thermometer is a superior alternative to thermocouples, which are soon damaged and worn by contact with the product, respond too slowly and introduce lags into the system that result in poor control.
At the drier exit chute, the thermometer sights onto a stream of aggregate. The RT8A output can be used to indicate aggregate temperature, or utilised in a closed loop control system to control the burner, thus minimising fuel wastage and maximising efficiency whilst controlling aggregate temperature.
During mixing, the batch nature of the process precludes automatic burner control - but knowledge of the hot stone temperature in the batch heater and its subsequent effect on binder and filler temperature is a useful aid to process control. Once in the mixer, the temperature of the material cannot be adjusted; but again, measurement at this point permits rejection of a single batch if it falls outside temperature specification limits, avoiding contamination of acceptable material.
Similarly, installing an RT8A thermometer at the mixer exit sighted onto the stream of coated asphalt as it falls from the mixer/storage bin into the delivery vehicle provides a final opportunity to reject out-of-specification product.
Temperature control is especially critical in continuous-production, drum-mix asphalt plants, where even slight fluctuations in final mix temperature can result in large volumes being rejected.
In this situation, the RT8A thermometer is mounted to sight on the stream of coated material as it leaves the discharge chute prior to the elevator system. The thermometer output can also be fed into a chart recorder, or used to control an automatic burner control system.
Reader inquiries:
Elizabeth Hilderley
US Marketing Communications Coordinator
Land Instruments International
10 Friends Lane
Newtown, PA 18940-1804, USA
Tel: (215) 504 8000
Fax: (215) 504 0879
Email: irsales@landinstruments.net
Internet: www.landinstruments.net
