ATI Technologies UniSens A12 User Manual

O & M Manual

UniSens

2-Wire Gas Transmitter

Home Office European Office

Analytical Technology, Inc. ATI (UK) Limited
6 Iron Bridge Drive Unit 1 & 2 Gatehead Business Park
Collegeville, PA 19426 Delph New Road, Delph
Phone: [phone] Saddleworth OL3 5DE
610-917-0991 Phone: [phone]
Fax: [phone] Fax: + 44 (0)1457-874-468
Email: [e-mail] Email: [e-mail]
Web: www.Analyticaltechnology.com

Fax: [phone] Fax: + 44 (0)1457-874-468

Series A12 Unisens 2-Wire Transmitter

TABLE OF CONTENTS

INTRODUCTION ....................................................................................................................................................3

AUTO-TEST OPTION ..............................................................................................................................4

DUCT MOUNTED SENSORS ..................................................................................................................6

SPECIFICATIONS ...................................................................................................................................................7

INSTALLATION ........................................................................................................................................................8

MECHANICAL MOUNTING ...................................................................................................................8

DUCT MOUNT SENSOR INSTALLATION ...........................................................................................10

SENSING MODULE REMOVAL ............................................................................................................11

CHANGING GAS SENSOR TYPE ...........................................................................................................11

ELECTRICAL CONNECTION .................................................................................................................................12

OPERATION ............................................................................................................................................................14

START-UP .................................................................................................................................................14

STARTUP DELAY ....................................................................................................................................15

FRONT PANEL MAGNETIC CONTROLS .............................................................................................15

LIQUID CRYSTAL DISPLAY .................................................................................................................16

MENU SEQUENCE .................................................................................................................................................17

TRANSMITTER MODE SELECTION .....................................................................................................19

INFORMATION MODE ...........................................................................................................................19

TEST MODE ..............................................................................................................................................19

MANUAL AUTO-TEST ACTIVATION ..................................................................................................19

ANALOG OUTPUT SIMULATION .........................................................................................................20

CALIBRATION .........................................................................................................................................................21

SENSING MODULE ZERO ADJUSTMENT ...........................................................................................22

SENSING MODULE SPAN ADJUSTMENT ...........................................................................................23

CALIBRATION OF DUCT MOUNT SENSORS .....................................................................................24

MA OUTPUT ADJUSTMENT ..................................................................................................................25

UNDER RANGE ENABLE/DISABLE SELECTION ..............................................................................25

AUTO-TEST ENABLE/DISABLE SELECTION .....................................................................................25

ERROR MESSAGES ................................................................................................................................26

FIGURES

Figure 1 - UniSens Transmitter Components ............................................................................................... 5

Figure 2 - UniSens Transmitter w/Duct Sensor Components ...................................................................... 6

Figure 3 - Overall Dimensions ...................................................................................................................... 8

Figure 4 - Wall Mounting Bracket ................................................................................................................. 9

Figure 5 - Duct Mount Sensor Installation .................................................................................................. 10

Figure 6 - Electrical Connections ................................................................................................................ 12

Figure 7 - Remote Electrical Connections .................................................................................................. 13

Figure 8 - UniSens Front Panel .................................................................................................................. 15

Figure 9 - Liquid Crystal Display ................................................................................................................. 16

Figure 10 - Transmitter Program Chart ...................................................................................................... 17

Figure 11 - Sensor Calibration Adapter Assemblies .................................................................................. 22

Figure 12 - Duct Mount Sensor Calibration ................................................................................................ 24

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Series A12 Unisens 2-Wire Transmitter

GENERAL GASES

OXIDANT GASES

ACID GASES

HYDRIDE GASES

INTRODUCTION

UniSens is a two-wire gas transmitter for use in monitoring hazardous gases in ambient air. It is
designed to monitor gas concentration in areas around storage cylinders, process piping, or gas feed
equipment in virtually any type of industrial plant environment.

The name UniSens signifies the fact that this is a Universal Sensor System. ATI sensor
modules can be interchanged on the universal transmitter to easily reconfigure for a different gas or
range. Sensing modules are available for monitoring a variety of gases and ranges as shown in Table 1.

TABLE 1

GAS CODE NO. STD. RANGE MIN. RANGE MAX. RANGE

Alcohol 39 0-500 PPM 0-500 PPM 0-2000 PPM

Ammonia 15 * 0-100 PPM 0-50 PPM 0-1000 PPM

Carbon Monoxide 16 * 0-100 PPM 0-50 PPM 0-1000 PPM

Ethylene Oxide 37 0-20 PPM 0-20 PPM 0-200 PPM

Formaldehyde 38 0-20 PPM 0-20 PPM 0-200 PPM

Hydrogen 18 0-4 % 0-2000 PPM 0-10 %

Nitric Oxide 25 0-50 PPM 0-25 PPM 0-500 PPM

Oxygen 19 0-25% 0-10% 0-100%

Phosgene 20 0-2 PPM 0-2 PPM 0-200 PPM

Bromine 10 * 0-2 PPM 0-2 PPM 0-100 PPM

Chlorine 11 * 0-10 PPM 0-2 PPM 0-100 PPM

Chlorine Dioxide 12 * 0-2 PPM 0-2 PPM 0-100 PPM

Fluorine 13 * 0-2 PPM 0-2 PPM 0-100 PPM

Hydrogen Peroxide 34 0-10 PPM 0-10 PPM 2000 PPM

Iodine 35* 0-10 PPM 0-2 PPM 0-100 PPM

Ozone 14 * 0-2 PPM 0-2 PPM 0-100 PPM

Hydrogen Chloride 21 * 0-20 PPM 0-10 PPM 0-200 PPM
Hydrogen Cyanide 22 * 0-20 PPM 0-10 PPM 0-200 PPM
Hydrogen Fluoride 23 * 0-20 PPM 0-10 PPM 0-200 PPM

Hydrogen Sulfide 24 * 0-50 PPM 0-10 PPM 0-500 PPM

Nitrogen Dioxide 26 * 0-20 PPM 0-5 PPM 0-200 PPM

Sulfur Dioxide 27* 0-20 PPM 0-10 PPM 0-200 PPM

General Acid Gases 36 * 0-20 PPM 0-5 PPM 0-200 PPM

Arsine 28 0-1000 PPB 0-1000 PPB 0-100 PPM

Diborane 29 0-1000 PPB 0-1000 PPB 0-100 PPM

Germane 30 0-1000 PPB 0-1000 PPB 0-100 PPM

Hydrogen Selenide 31 0-1000 PPB 0-1000 PPB 0-100 PPM

Phosphine 32 0-1000 PPB 0-1000 PPB 0-1000 PPM

Silane 33 0-10 PPM 0-1 PPM 0-100 PPM

* Indicates that Auto-Test is available for standard ranges and lower.

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Series A12 Unisens 2-Wire Transmitter

UniSens transmitters, also designated Series A12, are loop-powered devices capable of
operating from DC power supplies between 12 and 30 VDC. Normally, this transmitter will be powered
from the 24 VDC supply from a plant wide monitoring computer, a data logger, or an alarm systems that
supplies the DC voltage. The output of the transmitter is a 4-20 mA signal which is linear with respect to
concentration over the range of the sensing module.

Construction of the UniSens transmitter is modular to allow simple installation and maintenance
as shown in Figure 1 on the next page. The transmitter electronics is housed in an aluminum shell with
an 11 pin relay plug on the bottom. The outer housing is an explosion-proof and weatherproof enclosure
with a relay base mounted inside. The transmitter electronics module simply plugs into the relay base,
and all wiring connections are made to that base. Figure 1 shows an exploded view of a complete
UniSens transmitter with sensing module.

The sensing elements used in the UniSens are electrochemical sensors manufactured by ATI.
These sensors are designed for use in ambient air or in ventilation ducts at temperatures of -30° to +50°
C (some sensors rated to -40° C, oxygen sensors rated to -10° C) and at relative humidities between 20
and 98% RH. Use of these sensors in extremely dry air or in condensing gas streams is not
recommended.

Each sensing element is incorporated into a snap-in sensing module, which also contains
electronic memory that is read by the transmitter. This memory contains information on what type of gas
sensor is contained in the module, the range of that particular module, and the calibration constants for
the sensor. When the module is snapped into a transmitter, this data is read into the transmitter
electronics and information related to the module is displayed on the LCD display on the transmitter.
Because all calibration data is stored in the sensing module, these modules can be calibrated using any
spare transmitter and simply snapped into any other transmitter for operation. This unique feature
eliminates the need for field calibration.

AUTO-TEST OPTION

UniSens transmitters are available with an optional feature that eliminates much of the manual
response testing required for toxic gas detection systems. This feature is referred to as Auto-Test, and
consists of a miniature electrochemical gas generator close coupled to the sensor. The generator
produces a "puff" of gas when activated by the transmitter. The response of the sensor is monitored
during this test to be sure that it is still responding to the particular gas, and the output of the transmitter is
driven below 3.7 mA if the sensor does not respond. At the same time, the LCD display indicates that
there was an Auto-Test failure.

The Auto-Test sensor check occurs automatically every 24 hours so that the sensor response is
verified daily. In addition, the Auto-Test can be activated manually at any time using the controls on the
front of the transmitter. During the Auto-Test cycle, the 4-20 mA output is held at 4 mA so that receiving
devices do not alarm during the test. Because most users manually test toxic gas sensor response once
a week, the Auto-Test feature can pay for itself very quickly in reduced labor cost.

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Series A12 Unisens 2-Wire Transmitter

Figure 1 - UniSens Transmitter Components

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Series A12 Unisens 2-Wire Transmitter

DUCT MOUNTED SENSORS

A special sensor design is available as an option that allows toxic gas sensors to be
inserted into a duct or pipe through a special adapter. This system is designed to allow gas
monitoring in enclosed spaces with easy removal of the sensor for service. The special
mounting fitting provides a method for feeding calibration gas to the sensor without complete
removal from the duct.

Duct mount sensors are provided with a special interface cable so that the transmitter
electronics may be mounted a short distance from the sensing location. Figure 2 below shows
the components of the duct insertion version of the A12 gas transmitter.

Figure 2 - UniSens Transmitter w/Duct Sensor Components

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Series A12 Unisens 2-Wire Transmitter

SPECIFICATIONS

The following general specifications refer to the UniSens transmitter. Because each sensing
module contains a different sensor, there are specification differences for each gas.

Gas Type: Customer selected from available sensor list.
Range: Supplied with standard range for each gas unless otherwise specified.
Display: 4 1/2 digit LCD
Accuracy: Generally ±5% of value, but limited by available calibration gas accuracy.
Electronic Repeatability: ±1%
Electronic Linearity: ±0.5%
Zero Drift: Sensor dependent, but generally less than 1% of full scale per month, non-cumulative.
Span Drift: Application dependent, but generally less than 3% per month.
Under Range Trip: -20% (when enabled)
Output: Loop-powered 4-20 mA, 750 ohms maximum at 24 VDC loop power
Power: 12-30 VDC
Enclosure: NEMA 4X and Explosion-proof cast aluminum, Class 1, Div. 1, Groups B, C, & D.
Controls: Magnetic links activated externally through glass window. Non-intrusive calibration.
Operating Temperature: -30º to +55º C (except oxygen, which is -10º to +55º C)
Sensor: Modular plug-in unit with calibration data, gas type, and range in sensor memory.
Optional Sensor: Duct insertion sensor with 5 foot interface cable.
Sensor Pressure Limits: 7-30 PSIA (0.5-2 Bar)
Weight: 4 lbs. (1.8 Kg.)
Approvals: CSA Certificate #LR 101166 (Not valid for duct mount sensor)

Intrinsically safe when used with an approved I.S. barrier.
Explosion-proof; Class I, Groups B, C, & D; Class II, Groups E & F, Class III without barrier

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Series A12 Unisens 2-Wire Transmitter

INSTALLATION

Installation of a UniSens transmitter requires mechanically mounting the enclosure, grounding
the enclosure, and connecting DC power to the system.

MECHANICAL MOUNTING

Figure 3 shows the dimensions of the transmitter enclosure and the location and size of the
electrical conduit connection. When used in a classified area, and explosion-proof seal should be
installed as required by the local electrical code. The conduit or cable gland entry into the enclosure must
be sealed with Dow Corning 732 multipurpose sealant. The sealant should be liberally applied to the 3/4­14 NPT thread on the entry nipple or cable gland before installation. If conduit is used, it must also be
sealed internally at the entry point to the housing. This is required to prevent water condensation inside
the conduit from draining into the enclosure.

- WARNING - Failure to seal the conduit entry or cable gland will result in water entering the
enclosure causing damage or failure to the transmitter electronics.

Figure 3 - Overall Dimensions

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Series A12 Unisens 2-Wire Transmitter

The transmitter enclosure can be mechanically supported by the conduit if proper conduit
fasteners are used. A mounting bracket is supplied with the transmitter for fastening the transmitter
enclosure to a wall or mounting plate. Figure 4 shows the hole center dimension for that mounting
bracket. The mounting bracket attaches to the back of the enclosure with 4 screws supplied with the
bracket.

Figure 4 - Wall Mounting Bracket

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Series A12 Unisens 2-Wire Transmitter

DUCT MOUNT SENSOR INSTALLATION

Duct mounted sensors are designed to be inserted into an air duct or pipe through a special
adapter fitting (part number 00-0814). This fitting has a 1” MNPT thread on the front for adapting to the
duct or pipe. The actual duct adapter is customer supplied.

Installation of this sensor requires that the 00-0814 adapter be screwed into the customer
supplied adapter as shown in Figure 5 below. Screw in the adapter so that the calibration gas inlet port is
oriented in a direction that gas tubing can easily be connected. Once the adapter is in place, the sensor
will slide into the adapter easily. However, it is recommended that the sensor not be installed in the fitting
until you are ready to start up the transmitter. This is especially true during construction when dust and
dirt may be blowing through the duct system. Fouling of the sensor may result.

Figure 5 - Duct Mount Sensor Installation

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