Teledyne Model 300EU The Relay Pca, Temperature Control of the Convection Oven, M300EU, 05831 Rev

THEORY OF OPERATION	M300EU
	Addendum to M300E/EM Manual P/N 04288

10.3.2. THE RELAY PCA

The information found in Section 10.4.5 of the M300E/EM Operators Manual (P/N 04288) is applicable to the M300EU with the following exception(s):

10.3.2.1. Temperature Control of the Convection Oven

The information found in Section 10.4.5.1 of the M300E/EM Operators Manual (P/N 04288) is applicable to the M300EU with the following exception(s):

•There are two heaters attached to either side of the optical bench (see Figure 3-1)that radiate heat into the insulated, oven area of the analyzer. Each heater has a fan attached to it that circulates the heated air throughout the oven airspace.

•The CPU senses the temperature level form different places inside the oven area and determines the overall temperature of the oven. Eventually, all of the components within the oven area will stabilize at the same temperature. This usually takes about 2 hours after the instrument is turned ON.

•A separate fan blows directly on the A-to-D conversion circuitry of the motherboard to more keep it at the same temperature as the oven airspace in order to eliminate any temperature-coefficient related offset.

Figure 10-5: M300EU Heating Control Block Diagram

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