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Please your help with this question:
We wish to control the outlet temperature of a boiler. We will measure the outlet temperature, and send this signal to a controller. The controller gives a 4 - 20 mA output signal. This signal will be used to control a modulating valve, which will open/close, so as to increase / decrease gas that is being burned, to heat up the boiler. The greater the amount of gas, the greater the amount of heat generated. The smaller the amount of gas, the smaller the amount of heat. The valve is FAIL SAFE (i.e. a bigger signal will cause it to open, and a smaller signal will cause it to close. If it loses it’s signal, it will revert to the closed position). Please determine what the action of the controller should be (i.e. DIRECT or REVERSE / INDIRECT).
We wish to control the outlet temperature of a boiler. We will measure the outlet temperature, and send this signal to a controller. The controller gives a 4 - 20 mA output signal. This signal will be used to control a modulating valve, which will open/close, so as to increase / decrease gas that is being burned, to heat up the boiler. The greater the amount of gas, the greater the amount of heat generated. The smaller the amount of gas, the smaller the amount of heat. The valve is FAIL SAFE (i.e. a bigger signal will cause it to open, and a smaller signal will cause it to close. If it loses it’s signal, it will revert to the closed position). Please determine what the action of the controller should be (i.e. DIRECT or REVERSE / INDIRECT).