A helpline or hotline, or a telephone line providing customers or clients with direct access to a company or professional service, can be a useful resource when used in an effective, efficient manner.
Every different application of thermocouples demands that you choose a shape, size and material to match the process. That’s all this column deals with. Matters of temperature, environment, thermocouple alloys and construction materials are largely outside this month’s topic and are for another day.
When you point and shoot most infrared thermometers, you need to be sure that you are on target and that your sensor is capturing the radiated energy from all of the field of view.
by ArthurHolland | September 1, 2006 | Comments (0)
When you have to measure the temperature of the untouchable and have ruled out
using the thermocouple and the RTD, your best choice is usually one of the many
infrared thermometers (also known as optical pyrometers). The
sensing technology is the same for hand-held as for fixed-position units that
monitor continuously.
Heaters that incorporate one or other of the many nickel/chrome alloy wires and ribbons are widely popular, due to attributes such as low cost; a wide choice of size and shape; versatility of construction; robust performance; easily controlled due to minimal resistance change with temperature and service life; and tolerance to thermal cycling.
There is no limit to the ways in which you can deliver resistance heating to the
material in your process. Chances are you will be looking for a heater that
incorporates one or other of the many nickel/chrome alloy wires and ribbons.
In my last column, I began to review how the controller varies power to the heater. I’ll conclude this series with power feedback, heat and cool cycle times, balancing heat and cool, and controlling cooling zones.
by ArthurHolland | February 1, 2006 | Comments (0)
In my last column, I reviewed the elements of a controller that can throttle back the power well ahead of the temperature reaching setpoint and provide a way to defeat temperature overshoot and cycling: a PID (proportional + integral + derivative) controller. Among the parameters that you adjust to optimize (or tune) your controller are the proportional band, integral time and derivative time. I’ll pick up with tuning your PID controller.
by ArthurHolland | January 31, 2006 | Comments (0)
This month, as promised, I’ll show the elements of a controller that
can throttle back the power well ahead of the temperature reaching
setpoint and provide a way to defeat temperature overshoot and cycling.
Figure 1 shows the elements of a controller that would achieve this,
along with a thermocouple and a controlled load.
by ArthurHolland | November 1, 2005 | Comments (0)
This month, I continue looking at normal and abnormal behavior of
extruders, picking up with cooling issues and then beginning to look at
control principles to minimize overshoot in extruders.
