Teledyne 9110AH - Nitrogen oxides analyzer - Manual (Page 84)

TELEDYNE Model 9110AH NO
X
Analyzer Operator Manual, 01620, Rev. F
6-2
6.2 Zero/Span Valves Option
The Zero/Span Valve option consists of a manifold of stainless steel valves plus drive
electronics connected to the CPU. The Option consists of two variations. Option 50 has 2 - 2-
way valves, 1 3-way valve and operates in 3 modes:
1. Sample mode, all 3 valves off, sample gas flows through the sample port to the instrument.
2. Zero mode, sample-cal valve is energized to shut off sample flow, zero valve is energized to
input zero gas.
3. Span mode, sample-cal valve is energized to shut off sample flow, span valve is energized
to input low concentration range span gas.
Option 52 consists of all of the features in Option 50 plus a second span valve to allow a low
and high concentration of span gas.
See Figure 2-5 for valve location. Fittings on the rear panel are for two concentrations of span
gas plus zero gas. (See Figure 2-2 and Figure 2-3) The valves are can be operated by several
methods shown in Table 6-1.
Table 6-1: Zero/Span Valve Operation
Mode Description Reference Section
1. Front panel operation via
CALS and CALZ buttons. Calibration Section 7 - Manual Zero/Span Check.
2. Automatic operation using
AUTOCAL Setup and use of AUTOCAL is described in Table 6-2, and
Section 7.2
3. Remote operation using the
RS-232 interface Setup described in Section 6.2 Operation of AUTOCAL
described in Section 7.2
4. Remote operation using
external contact closures Section 7.4 - Automatic operation using external contact
closures. Table 7-7 and Section 9.3.4.3
Zero and span gas inlets should supply their respective gases in excess of the demand of the
Analyzer. Supply and vent lines should be of sufficient length and diameter to prevent back
diffusion and pressure effects. See Figure 2-3 for fitting location and tubing recommendations.
6.2.1 Autocal - Setup Zero/Span Valves
The Zero/Span valves can be set up to operate automatically. Table 6-2 in this section describes
Autocal setup.