HOW TO SELECT HEATER SIZE:
- Establish maximum temperature at which part will operate.
- Calculate total wattage needed to produce this temperature.
- Establish the diameter and length of the Heater that is best suited to the dimensions of your part.
- Estimate the number of HEATERS needed for even heat. Divide total wattage required by the number, of Heaters to determine wattage rating of each unit.
- Determine the watt density of the size selected.
- Determine fit.
- Use graph below to make certain that the watt density you have established does not exceed the maximum allowable watt density of the cartridge. Read along the part temperature curve to the horizontal line representing the fit you have established. From this intersection point read down to the Watt Density Scale. This is the maximum watt density you should use. A higher rating would shorten cartridge life. A lower rating prolongs cartridge life.
- If you find that watt density is excessive you can correct in three ways: (1) Use a tighter fit (2) Use more or larger heaters (3) Use lower wattage. (In this ⑶se allow for longer heat up time.)
- Tight fits are achieved by grinding OD of cartridge and reaming the hole size accurately.