Teledyne 3000PA operating instructions Range Function, Setting the Analog Output Ranges

Percent Oxygen Analyzer Operation 4

4.6The Range Function

The Range function allows the operator to program up to three concen- tration ranges to correlate with the DC analog outputs. If no custom ranges are defined by the user, the instrument defaults to:

Low = 0–1.00 %

Med = 0–5.00 %

High = 0–10.00 %.

The Model 3000PA is set at the factory to default to autoranging. In this mode, the microprocessor automatically responds to concentration changes by switching ranges for optimum readout sensitivity. If the current range limits are exceeded, the instrument will automatically shift to the next higher range. If the concentration falls slightly below full scale of the next lower range, the instrument will switch to that range. A corresponding shift in the DC percent-of-range output, and in the range ID outputs, will be noticed.

The autoranging feature can be overridden so that analog output stays on a fixed range regardless of the oxygen concentration detected. If the concentration exceeds the upper limit of the range, the DC output will saturate at 1 V dc.

However, the digital readout and the RS-232 output of the concentra- tion are unaffected by the fixed range. They continue to read accurately with full precision. See Front Panel description in Chapter 1.

4.6.1 Setting the Analog Output Ranges

To set the ranges, enter the range function mode by pressing the

Range button on the front panel.

L—1.00 M—5.00

H—10.00 Mode—AUTO

Use the < > arrow keys to blink the range to be set: low (L), medium (M), or high (H).

Use the ∆∇ arrow keys to enter the upper value of the range (all ranges begin at 0 %). Repeat for each range you want to set. Press Enter to accept the values and return to Analyze mode. (See note below.)

Note: The ranges must be increasing from low to high. For example, if range 1 is set as 0–1 % and range 2 is set as 0–10 %, range 3 cannot be set as 0–5 % since it is lower than range 2.

Teledyne Analytical Instruments 4-15