Rear Panel - Teledyne 2120 Operating Instructions Manual

Introduction
CAUTION: THE DISPLAY METER INDICATES A LOW LEVEL
IMPURITY ANALYSIS WHILE IN THIS MODE. THIS IS
NOT THE ACTUAL NITROGEN CONCENTRATION.
• Range Switch: Used to select the measurement range maximum
ppm.
• Digital Panel Meter (DPM) — Displays the nitrogen
content of the sample stream in ppm.
Note: When there is no sample flow or there is a loss of
ionization voltage, or when the impurities are out of range
(i.e. , > 2 ppm in the 2 range, > 20 ppm in the 20 range,
and > 200 ppm in the 200 range), the DPM displays "1"
(the number one with a decimal point and no additional
digits). The maximum number the meter reads before it
goes to "1" is 1.999 in the 2 ppm range, 19.99 in the 20
ppm range, or 199 99 in the 200 ppm range.
• Zero Potentiometer: Used for calibration with zero gas.
• Span Potentiometer: Used for calibration with span gas.
• Sample Flow Rotameter: Monitors flow rate of gas to the
analytical cell.

1.5 Rear Panel

Connections and other controls are located on the rear panel of the
analyzer, as shown in Figure 1-2. This includes:
• Power Entry Module — Main power on/off function, connector
for input power cable, and fuse holder for the analyzer. This
module protects the analyzer from input power surges and the
power supply from short circuits.
• Sample Input Port — 1/4-in (0.64 cm) VCR fitting marked
INPUT. This fitting is used to connect the sample inlet line to
the analyzer.
Teledyne Analytical Instruments
4
Model 2120