Teledyne 6600 manual Precautions

3 Operation Model 6600

tration exceeds the upper limit of the range, the DC output will saturate at 1 V dc (20 mA at the current output).

However, the digital readout and the RS-232 output of the concentration are unaffected by the fixed range. They continue to read beyond the full-scale settinguntilamplifiersaturationisreached.Belowamplifiersaturation,the overrangereadingsareaccurateUNLESStheapplicationuseslinearizationover the selected range.

The concentration ranges can be redefined using the Rangefunction Manual screen, and the application gases can be redefined using the System function, ifthey are not already defined as necessary.

CAUTION: Redefining applications or ranges might require relinearization and/or recalibration.

Tosetupautomaticranging:

Enter the Range function to start the Range function.

Select range mode : AUTO

If above screen displays MAN, use the UP/DOWN switch to Select AUTO, and Enter.

Press Escape to return to the previous Analyze Function.

3.6.3 Precautions

The Model 6600 allows a great deal of flexibility in choosing ranges for automatic range switching. However, there are some pitfalls that are to be avoided.

Ranges that work well together are:

•Ranges that have the same lower limits but upper limits that differ by approximately an order of magnitude

•Ranges whose upper limits coincide with the lower limits of the next higher range

•Ranges where there is a gap between the upper limit of the range and the lower limit of the next higher range.

Range schemes that are to be avoided include:

•Ranges that overlap

3-26 Part I

Teledyne Analytical Instruments