I am seeking someone to write a program to Monitor control and data log an autoclave. This would mean the control of temperature and pressure over time, typical cure cycle is between 1 and 12 hours. Temperature would have mulitple ramps and soaks from ambient to no more than 350F. The output signal is a 4-20 milliamp driving an SCR. Temp input is a J type thermocouple. The temperature cycle is based on time with checks that it has reached the previous ramp or soak within a specified range, typical of an off the shelf PID controller for ramp and soak. Cooling is a digital output with water flow through a radiator. Pressure is also digital output through a valve, max pressure is 90 psi. Both cooling and pressure outputs are 5VDC. Vacuum is applied through a manifold and a valve, the output is also 5VDC. A typical cycle is attached in the excel spread sheet. Two interfaces would be needed, one for the general operator to choose from a menu/list a desired recipe. The second interface would be where the recipe is built, ie temp, pressure, vacuum against time. Vacuum should be able to be turned on and off against time or against pre-determined heat levels. Pressure again is turned on against time and or predetermined heat levels. Vacuum is always full on or full off. Pressure will ramp up and down, the same as the temperature control. Screen will be touch screen so all buttons and must be large, keyboard and mouse will be available for recipe building only. Data acquisition is the main J thermouple and 6 additional thermocouples, data would be acquired when thermocouple is in range, ie plugged in, otherwise ignored. Pressure is data logged and controlled from a -50mv to +50mv sensor, vacuum is -10vdc to +10vdc sensor. Presently all input signals are running through an anolog devices 16 channel back plane with isolated inputs, Thermocouples are 0-5Vdc, Pressure and Vacuum are conditioned to -5vdc to +5vdc. The output to the SCR for heating is also conditioned on the same backplane at 0 to 5vdc from the controlling source. Data logging of the 6 independent and 1 primary thermocouple is required along with the pressure and vacuum. Safety through the control system is a digital input, normaly open switch for pressure and temperature is also measured but not logged from the elements with a max safety temperature. The 1st of the independent thermocouple inputs is also used as a max safety as well. Note there are mechanical and electro-mechanical safety devices independent of the control. Please place you enquiries with Lsargent@appliedcomposites.com
