Yokogawa IAC-24 Integral Automatic Calibration Unit User Manual

Model iac-24-22-e-a installation guide

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Model IAC-24-22-E-A
Installation Guide

The IAC-24 auto-calibration unit mounts directly to the Yokogawa ZR22G oxygen detector. The
connections are made via 1/4” reference air and calibration gas ports located on the detector and the
1/4” fittings on the IAC-24. The IAC-24 uses solenoid manifolds that automate the calibration process;
the solenoid are powered by the ZR402G analyzer. The analyzer activates the solenoid allowing the
calibration and reference gas to flow to the detector; since the manifold has a fixed orifice no flow
adjustment is needed.

General Specifications:

Input pressure:

7 psig +/- 2 psig

Output Flow:

Ref: 0.8 SLPM
Cal: 0.6 SLPM

Input Flow:

Min: 3.5 SLPM


4.5” x 3.5” x 1.9” (w 115mm x h 89mm x t 49mm)

Electrical requirements:

24 V DC


2 x 1/4” swage type pneumatics fitting
3 pin quick connect fitting

Ambient Temp:

194°F (90°C)


The following guidelines should be used when selecting a location for the calibration unit:
1) Easily accessible for maintenance and inspections
2) Ambient temperature does not exceed 194°F (90°C)
3) Humidity is moderate and no corrosive gases are present
4) Instrument air is available

1.2 Calibration/Reference Gas
Never use pure nitrogen. Typically, 1% instrument grade O2 balanced in nitrogen is used for zero
gas; however, an O2 mixture between 0.4% and 8% is acceptable. A compressed gas cylinder
containing certified gas mixtures fitted with a dual stage regulator should be used.
Span: A clean, dry air source, such as instrument air, is recommended. Install an in-line filter before the
calibration unit to remove any moisture or dirt. A regulator must be attached to the instrument air
source to provide the appropriate working pressure for the calibration unit.
Reference: Reference air is from the same source as the span gas. The reference air flows to the
backside of the zirconia cell and is used at all times. The calibration unit is plumbed to provide a
continuous flow rate of reference air, as well as calibration gas flow during calibration.

Yokogawa Corporation of America
2 Dart Road Newnan, Georgia U.S.A. 30265
Tel: 1-800-888-6400 Fax: 1-770-251-2088

IM 11M1 2D01-91-E-A

©Copyright March. 2005

1st Edition March, 2005