Detcon FP-524D-HRT User Manual

INSTRUCTION MANUAL

DETCON, Inc.

Detcon Model FP-524D-HRT

PGM 1

HOUSTON,TEXAS

TM

MicroSafe LEL Gas Sensor

ALM ALM

FLT 1 2 CAL

PGM 2

FP-524D-HRT Combustible Gas Sensor

(0 – 100% LEL) with HRT Bridge

4055 Technology Forest Blvd, Suite 100,

The Woodlands, Texas 77381

Ph.281.367.4100 / Fax [phone]

www.detcon.com

April 23, 2012 • Document #3603 • Revision 0.1

Page left intentionally blank

Model FP-524D-HRT

FP-524D-HRT Instruction Manual ii

Model FP-524D-HRT

Table of Contents

1. Introduction............................................................................................................................................1

1.1 Description.....................................................................................................................................1

1.2 Modular Mechanical Design...........................................................................................................3

2. Installation ............................................................................................................................................. 5

2.1 Operational Guidelines for Safe Use...............................................................................................5

2.2 Sensor Placement...........................................................................................................................5

2.3 Sensor Contaminants and Interference............................................................................................6

2.4 Mounting Installation .....................................................................................................................7

2.5 Electrical Installation......................................................................................................................8

2.6 Field Wiring...................................................................................................................................9

2.7 Initial Start Up .............................................................................................................................10

3. Operation .............................................................................................................................................12

3.1 Programming Magnet Operating Instructions................................................................................12

3.2 Operator Interface ........................................................................................................................13

3.3 Normal Operation ........................................................................................................................14

3.4 Calibration Mode (AutoZero and AutoSpan)................................................................................15

3.4.1 AutoZero .................................................................................................................................15

3.4.2 AutoSpan.................................................................................................................................15

3.5 Program Mode .............................................................................................................................17

3.5.1 View Sensor Status ..................................................................................................................18

3.5.2 Set AutoSpan Level ................................................................................................................. 19

3.5.3 Set Gas Factor.......................................................................................................................... 19

3.5.4 Set Cal Factor ..........................................................................................................................21

3.5.5 Set Bridge Voltage...................................................................................................................21

3.5.6 Signal Output Check................................................................................................................22

3.5.7 Restore FactoryDefaults.......................................................................................................... 22

3.6 Program Features ......................................................................................................................... 23

3.6.1 Operational Features ................................................................................................................ 23

3.6.2 Fault Diagnostic/Failsafe Features............................................................................................23

4. HRT Bridge.......................................................................................................................................... 26

4.1 Description...................................................................................................................................26

4.2 Connecting the HRT Bridge ......................................................................................................... 26

4.3 Operation..................................................................................................................................... 26

4.4 Operator Interface ........................................................................................................................27

4.4.1 Device Menu............................................................................................................................27

4.4.2 Diagnostics Menu ....................................................................................................................30

4.4.3 Device Setup Menu..................................................................................................................31

5. Service and Maintenance...................................................................................................................... 38

6. Troubleshooting Guide.........................................................................................................................40

7. Customer Support and Service Policy...................................................................................................43

8. FP-524D-HRT Sensor Warranty........................................................................................................... 44

9. Appendix..............................................................................................................................................45

9.1 Specifications...............................................................................................................................45

9.2 Spare Parts, Sensor Accessories, Calibration Equipment...............................................................47

9.3 Revision Log................................................................................................................................ 48

FP-524D-HRT Instruction Manual iii

Model FP-524D-HRT

List of Figures

Figure 1 Sensor Assembly Front View............................................................................................................ 1

Figure 2 Sensor Cell Construction ................................................................................................................. 2

Figure 3 Wheatstone Bridge ........................................................................................................................... 2

Figure 4 Response Curves .............................................................................................................................. 2

Figure 5 Circuit Functional Block Diagram .................................................................................................... 3

Figure 7 FP-524D-HRT Transmitter Module.................................................................................................. 3

Figure 8 LEL Sensor Housing with replaceable Sensor................................................................................... 4

Figure 9 Base Connector Board...................................................................................................................... 4

Figure 10 Typical Outline and Mounting Dimensions..................................................................................... 7

Figure 11 Typical Installation......................................................................................................................... 8

Figure 12 Sensor Connector PCB..................................................................................................................10

Figure 13 Magnetic Programming Tool.........................................................................................................12

Figure 15 Magnetic Programming Switches.................................................................................................12

Figure 16 FP-524D-HRT Software Flowchart...............................................................................................14

Figure 17 Primary Variables..........................................................................................................................28

Figure 18 Identification.................................................................................................................................29

Figure 19 Device Status Screen.....................................................................................................................30

Figure 20 FP Configuration Setup..................................................................................................................32

Figure 21 FP Calibration Screen....................................................................................................................33

Figure 22 DVM Connection ..........................................................................................................................36

Figure 23 HART Setup..................................................................................................................................37

Figure 24 Replaceable Combustible Gas Sensor ...........................................................................................40

List of Tables

Table 1 Wire Gauge vs. Distance.................................................................................................................... 9

Table 2 Gas/Cal Factors.................................................................................................................................20

Shipping Address:4055 Technology Forest Blvd, Suite 100, The Woodlands Texas 77381

Phone: [phone] • Fax: [phone] • www.detcon.com • [e-mail]

FP-524D-HRT Instruction Manual iv

Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067

Model FP-524D-HRT

1. Introduction

1.1 Description

Detcon Model FP-524D-HRT LEL Combustible sensors are non-intrusive “Smart” sensors designed to detect
and monitor combustible gases in air. Range of detection is 0-100% LEL (Lower Explosive Limit). The
sensor features an LED display of current reading, fault, and calibration status. The Sensor is equipped with a
HRT Bridge Interface, analog 4-20mA output. The HRT Bridge interface provides bi-directional digital
communication with HART®-enabled devices. A primary feature of the sensor is its method of automatic
calibration, which guides the user through each step via fully scripted instructions displayed on the LED
display.

The microprocessor-supervised electronics are packaged as a plug-in replaceable Transmitter Module that is
housed in an explosion proof junction box. The Transmitter Module includes a four character alpha/numeric
LED used to display sensor readings, and the sensor’s menu driven features when the hand-held programming
magnet is used.

PGM 1

MODEL FP-524DHOUSTON,TEXAS

TM

MicroSafe LEL Gas Sensor

ALM ALM

FLT 1 2 CAL

PGM 2

Figure 1Sensor Assembly Front View

Catalytic Bead (Pellistor) Sensor Technology

The sensor technology is a poison-resistant catalytic bead type. Catalytic bead sensors show a strong response
to a long list of combustible gases. The sensor is supplied as a matched-pair ofdetector elements mounted in a
plug-in replaceable module. One bead is a catalytically active detector and the other is a non-active reference
detector. Each detector consists of a fine platinum wire coil embedded in aluminum oxide. A catalytic
mixture is applied to the active detector while the reference detector is treated so that oxidation of the gas does
not occur. This technique is referred to as non-selective and may be used to monitor most any combustible
gas. Detcon catalytic bead sensors are specifically designed to be resistant to poisons such as sulfides,
chlorides, and silicones. The sensors are characteristically stable and capable of providing reliable
performance for periods exceeding 5 years in most industrial environments.

FP-524D-HRT Instruction Manual Rev. 0.1 Page 1 of 48

Model FP-524D-HRT

Platinum Wire

Catalyst

Construction

of Detector

Bead

Alumina Bead

Catalytic Beads

Main Housing Insert

Printed Circuit Board
Gold Plated Pins

Figure 2 Sensor Cell Construction

Principle of Operation

Method of detection is by diffusion/adsorption. Air and combustible gases pass through a sintered stainless
steel filter and contact the heated surface of both the active and reference detectors. The surface of the active
detector promotes oxidation of the combustible gas molecules while the reference detector has been treated not
to support this oxidation. The reference detector serves as a means to maintain zero stability over a wide range
of temperature and humidity.

When combustible gas molecules oxidize on the surface of the active detector, heat is generated, and the
resistance of the detector changes. Electronically, the detectors form part of a balanced bridge circuit. As the
active detector changes in resistance, the bridge circuit unbalances. This change in output is conditioned by
the amplifier circuitry, which is an integral part of the sensor design. The response and clearing characteristics
of the sensor are rapid and provide for the continuous and accurate monitoring ofambient air conditions.

Sensor

Input

Voltage

Cell

Zero

Adjust

Compensator /
Reference Bead

Detector /
Active Bead

Output

Figure 3 Wheatstone Bridge

Performance Characteristics

The detector elements maintain good sensitivity to combustible gas concentrations in the Lower Explosive
Limit (LEL) range, as shown in the response curves in Figure 4. However, for gas concentrations significantly
above the LEL range (100% LEL = 5% by volume Methane), the bridge output begins to decrease.
Ambiguous readings above the LEL range dictate that alarm control logic be of the latching type, wherein
alarms are held in the “ON” position until reset by operations personnel.

Figure 4 Response Curves

FP-524D-HRT Instruction Manual Rev. 0.1 Page 2 of 48

Model FP-524D-HRT

4-20mA

Displa

y

Control

Pre-Amp

HART communication

Power Supply

1.2 Modular Mechanical Design

The Model FP-524D-HRT Sensor Assembly is completely modular and is made up of four parts:

1) FP-524D with HRT Bridge Plug-in Transmitter

2) Field Replaceable Combustible Gas Sensor

3) Connector PCB

4) Splash Guard.

FP-524D-HRT Plug-in Transmitter

The Plug-in Transmitter Module is a microprocessor-based package that plugs into the connector board located
in the explosion proof junction box. Circuit functions include extensive I/O circuit protection, sensor pre­amplifier, sensor temperature control, on-board power supplies, microprocessor, LED display, magnetic
programming switches, and a linear 4-20mA DC output with HART. Magnetic program switches located on
either side of the LED Display are activated via a hand-held magnetic programming tool, thus allowing non­intrusive operator interface with the Transmitter Module. Calibration can be accomplished without
declassifying the area. Electrical classifications are Class I, Division 1, Groups B C D.

Plug-In

Sensor

Element

Temperature

Micro-

Processor

I/O

Circuit

Protection

Figure 5 Circuit Functional Block Diagram

PGM 1

MODEL FP-524D-HRTHOUSTON,TEXAS

MicroSafe LEL Gas Sensor

TM

ALM ALM

FLT 1 2 CAL

PGM 2

Analog 4-20mA Out

Power In

Figure 6 FP-524D-HRT Transmitter Module

Field Replaceable Sensor

The Detcon combustible gas sensor is a field proven, replaceable type sensor. It can be accessed and replaced
in the field by unthreading the lower half of the sensor housing. The cell can then be unplugged and replaced.
The Detcon combustible gas sensor has an infinite shelf life and is supported by a 2 year warranty.

FP-524D-HRT Instruction Manual Rev. 0.1 Page 3 of 48

Replacable Sensor

Model FP-524D-HRT

Threaded Insert

O-ring

Main Housing

Figure 7 LEL Sensor Housing with replaceable Sensor

NOTE: The Field Replaceable Combustible Gas Sensor housing is constructed from 316 Stainless Steel in
order to maximize corrosion resistance in harsh environments.

Base ConnectorPCB

The base connector board is mounted in the Junction Box. The connector board includes lug-less terminal
connections for incoming power and MA output / HART Interface, and connections for the Combustible Gas
Replaceable Sensor.

Wiring to

Customer

Wiring

LEL Sensor

Figure 8 Base Connector Board

FP-524D-HRT Instruction Manual Rev. 0.1 Page 4 of 48

Model FP-524D-HRT

NOTE:

Met

hane and Hydrogen are lighter than air. Most other combustible gases are heavier

2. Installation

2.1 Operational Guidelines for Safe Use

1. Install sensor only in areas with classifications matching with those described on the approval label.
Follow all warnings listed on the label.

2. Ensure that the sensor is properly mounted in a vertical orientation with sensor facing down. Avoid
use of Teflon Tape, or any type of non-conductive pipe thread coating on the NPT threaded
connection.

3. Use ¾” NPT plugs properly rated for hazardous locations to block anyunused connections

4. Removal of the Junction box cover or threaded sensor housing (612-820000-000) violates the Ex d
protection method and hence power must be removed from the sensor prior its safe removal.

5. Ensure that the housing bottom and plug-in sensor are installed during operation. The housing bottom
should be threaded tightly to the sensor housing. Removal of the housing bottom violates the Ex d
protection method and hence power must be removed from the sensor prior to its safe removal.

6. Proper precautions should be taken during installation and maintenance to avoid the build-up of static
charge on the plastic splashguard of the sensor.

7. Do not operate the sensor outside of the stated operating temperature limits.

8. Do not operate the sensor outside the stated operating limits for voltage supply.

2.2 Sensor Placement

Selection of sensor location is critical to the overall safe performance of the product. Six factors play an
important role in selection of sensor locations:

(1) Density of the gas to be detected
(2) Most probable leak sources within the industrial process
(3) Ventilation or prevailing wind conditions
(4) Personnel exposure
(5) Maintenance access
(6) Additional Placement Considerations

Density

Placement of sensors relative to the density of the target gas is such that sensors for the detection of heavier
than air gases should be located within 4 feet of grade as these heavy gases will tend to settle in low lying
areas. For gases lighter than air, sensor placement should be 4-8 feet above grade in open areas or in pitched
areas ofenclosed spaces.

than air. Compare the molecular weight, density, or specific gravity of the target gas(es) with
that of air to determine appropriate placement.

FP-524D-HRT Instruction Manual Rev. 0.1 Page 5 of 48

Model FP-524D-HRT

NOTE:

In all installations the gas sensor sh

ould point straight down (refer to

Figure

10

).

Leak Sources

The most probable leak sources within an industrial process include flanges, valves, and tubing connections of
the sealed type where seals may either fail or wear. Other leak sources are best determined by facility
engineers with experience in similar processes.

Ventilation

Normal ventilation or prevailing wind conditions can dictate efficient location of gas sensors in a manner
where the migration of gas clouds is quickly detected.

Personnel Exposure

The undetected migration of gas clouds should not be allowed to approach concentrated personnel areas such
as control rooms, maintenance or warehouse buildings. A more general approach to selecting sensor location
is combining leak source and perimeter protection in the best possible configuration.

Maintenance Access

Consideration should be given to providing easy access for maintenance personnel. Consideration should also
be given to the consequences of close proximity to contaminants that mayfoul the sensor prematurely.

Improper sensor orientation may result in false readings and permanent sensor damage.

Additional Placement Considerations

The sensor should not be positioned where it may be sprayed or coated with surface contaminating substances.
Painting sensor assemblies is prohibited.

Although the sensor is designed to be RFI resistant, it should not be mounted in close proximity to high­powered radio transmitters or similar RFI generating equipment.

When possible mount in an area void of high wind, accumulating dust, rain, or splashing from hose spray,
direct steam releases, and continuous vibration. If the sensor cannot be mounted away from these conditions
then make sure theDetcon Harsh Location Dust Guard accessory is used.

Do not mount in locations where temperatures will exceed the operating temperature limits of the sensor.
Where direct sunlight leads to exceeding the high temperature-operating limit, use a sunshade to help reduce
temperature.

2.3 Sensor Contaminants and Interference

Detcon combustible gas sensors may be adversely affected by exposure to certain airborne substances. Loss of
sensitivity or corrosion may be gradual if such materials are present in sufficient concentrations.

The performance of the detector elements may be temporarily impaired during operation in the presence of
substances described as inhibitors. Inhibitors are usually volatile substances containing halogen compounds.
Inhibitors include halide compounds such as Cl2, ClO2, F2, HF, HCl, Br2, vinyl chloride, and methyl chloride.
Inhibition is typically a temporary effect and the detectors generally recover after short periods of operation
back in clean air.

Some background gases may act as poisoning agents and have a more damaging effect on the sensor.
Although the sensor is designed to be poison resistant, it does have physical limits. Poisoning gases deactivate

FP-524D-HRT Instruction Manual Rev. 0.1 Page 6 of 48

Model FP-524D-HRT

NOTE:

Do not use Teflon Tape or any other type of Pipe Thread material on the ¾” threads

the active detector’s catalytic ability and cause a permanent reduction in the span sensitivity. Examples of
typical poisons are: silicone oils and greases, siloxanes (HMDS), H2S, anti-knock petrol additives, and
phosphate esters. Activated carbon filters can be used to provide additional protection from poisoning in most
cases.

The presence of such inhibitors and poisons in an area does not preclude the use of this sensor technology,
although it is likely that the sensor lifetime will be shorter as a result. Use of this sensor in these environments
may require more frequent calibration checks to ensure safe system performance.

2.4 Mounting Installation

The FP-524D-HRT should be vertically oriented so that the sensor points straight downward. The explosion­proof enclosure or junction box would then typically be mounted on a wall or pole (See Figure 9). Detcon
provides a selection of standard junction boxes in both Aluminum and Stainless Steel.

unless the unit is mounted in a severe or harsh environment. Metal-on-metal contact must be
maintained to provide a solid electrical ground path. If Teflon Tape is used the Sensor must be
externally grounded using a ground strap.

When mounting on a pole, secure the Junction Box to a suitable mounting plate and attach the mounting plate
to the pole using U-Bolts. (Pole-Mounting brackets for Detcon Junction Box’s are available separately.)

6.985"

1

" mounting holes

4

6.125"

5.5"

3

NPT Ports

4

5.25"

8-32 tapped
ground point

LEL Sensor

2.1"

2"

0.5"

Cal Port

Splash Guard

Figure 9Typical Outline and Mounting Dimensions

4.6"

Wall (or other

mounting surface)

FP-524D-HRT Instruction Manual Rev. 0.1 Page 7 of 48

Model FP-524D-HRT

NOTE:

If a conduit run exits the secondary port, repeat the installation technique shown in

NOTE:

A conduit seal is typically required to be located within 18" of the J

-

Box and Sensor

NOTE:

The Detcon Warranty does not cover water damage resultin

g from water leaking into

2.5 Electrical Installation

The Sensor Assembly should be installed in accordance with local electrical codes. The sensor assemblies are
CSA/NRTL approved (US and Canada) for Class I, Division 1, Groups B, C, & D area classifications.

Proper electrical installation of the gas sensor is critical for conformance to Electrical Codes and to avoid
damage due to water leakage. Refer to Figure 10 and Figure 11 for proper electrical installation.

Figure 10.

In Figure 10, the drain allows H2O condensation inside the conduit run to safely drain away from the sensor
assembly. The electrical seal fitting is required to meet the National Electrical Code per NEC Article 500-3d
(or Canadian Electrical Code Handbook Part 1 Section 18-154). Requirements for locations of electrical seals
are covered under NEC Article 501-5. Electrical seals also act as a secondary seal to prevent water from
entering the wiring terminal enclosure. However, they are not designed to provide an absolute watertight seal,
especially when used in the vertical orientation.

Assembly. Crouse Hinds type EYS2, EYD2 or equivalent are suitable for this purpose.

the enclosure.

Conduit

Drain

"T"

EYS Seal Fitting

PGM 1

MODEL FP-524DHOUSTON,TEXAS

TM

MicroSafe LEL Gas Sensor

ALM ALM

FLT 1 2 CAL

PGM 2

Figure 10 Typical Installation

FP-524D-HRT Instruction Manual Rev. 0.1 Page 8 of 48

Model FP-524D-HRT

NOTE:

Any unused ports should be blocked with suitable ¾” male NPT plugs. Detcon

Over

-

Current

22

0.723mm

700

2080

3A200.812mm

1120

3350

5A181.024mm

1750

5250

7A161.291mm

2800

8400

10A141.628mm

4480

13,440

20A

NOTE 1:

Wiring table is based on stranded tinned copper wire and is designed to serve asa

NOTE 2:

Shielded cable is required for installations where cable

trays or conduit runs include

NOTE 3:

The supply of power should be from an isolated source with over

-

current protection

NOTE 4:

A 250 ohm load resistor is needed onthe 4

-

20 mA line when it is not being used.

supplies one ¾” NPT male plug with each J-box enclosure. If connections are other than ¾”
NPT, use an appropriate male plug of like construction material.

2.6 Field Wiring

Detcon Model FP-524D-HRT combustible gas sensor assemblies require three conductor connections between
power supplies and host electronic controller’s 4-20mA / HART interface. A 250 ohm load resistor is needed
on the 4-20 mA line when it is not being used. Wiring designations are DC+, DC-, and MA (sensor signal).
The maximum wire length between sensor and 24VDC source is shown in the Table below. The maximum
wire size for termination in the Junction Box is 14 AWG.

Table 1 Wire Gauge vs. Distance

AWG Wire Dia. Meters Feet

reference only.

high voltage lines or other possible sources of induced interference. Separate conduit runs are
highly recommended in these cases.

as stipulated in table.

Terminal Connections

CAUTION: Do not apply system power to the sensor until all wiring is properly terminated. Refer to
Section 2.7 Initial Start Up.

Protection

FP-524D-HRT Instruction Manual Rev. 0.1 Page 9 of 48

Model FP-524D-HRT

NOTE

: A 6

-

32 or 8

-

32 threaded exterior ground point is provided on most

junction boxes for

NOTE

: The 4

-

20mA signal is held constant at 4mA for the first two minutes after power up.

NOTE

: Do not use calibration gases in Nitrogen background gas mixtures. This will cause

Blue

Customer

Wiring

Yellow

Black
White

Figure 11 Sensor Connector PCB

Wiring to
LEL Sensor

a) Remove the junction box cover and unplug the Transmitter Module. Identify the terminal blocks for

customer wire connections.

b) Observing correct polarity, terminate the 3-conductor 4-20mA field wiring (DC+, DC-, and MA) to the

sensor assembly wiring in accordance with the detail shown in Figure 11.

c) Trim all exposed wire leads if they are not permanently landed in the terminal block.

d) Plug the Transmitter Module into the connector PCB and replace the junction box cover.

an external ground. If the Sensor Assembly is not mechanically grounded, an external ground
strap must be used to ensure that the sensor is electrically grounded.

2.7 Initial Start Up

Upon completion of all mechanical mounting and termination of all field wiring, apply system power in the
range of 12-28VDC (24VDC typical) and observe the following normal conditions:

a) FP-524D-HRT display reads “0”, and no fault messages are flashing.

b) A temporary upscale reading may occur as the sensor heats up. This upscale reading will decrease to “0”

% within 1-2 minutes of power-up, assuming there is no gas in the area of the sensor.

Initial Operational Tests

After a warm up period of 1 hour, the sensor should be checked to verify sensitivityto combustible gas.

Material Requirements

-Detcon PN 600-610000-000 Splash Guard with integral Cal Port -OR-

-Detcon PN 943-000006-038 Threaded Calibration Adapter

- Detcon PN 942-520124-050 Span Gas; 50% LEL methane/balance Air at fixed flow rate of 200-500cc/min.

FP-524D-HRT Instruction Manual Rev. 0.1 Page 10 of 48

Model FP-524D-HRT

significant reading inaccuracies.

a) Attach the calibration adapter to the threaded sensor housing. Apply the test gas at a controlled flow rate

of 200 - 500cc/min (200cc/min is the recommended flow). Allow 1-2 minutes for the reading to stabilize.
Observe that during the 1-2 minutes the display increases to a level near that of the applied calibration gas
value.

b) Remove test gas and observe that the display decreases to “0”.

Initial operational tests are complete. Detcon combustible gas sensors are factory calibrated prior to shipment,
and should not require significant adjustment on start up. However, it is recommended that a complete
calibration test and adjustment be performed 16 to 24 hours after power-up. Refer to span calibration
instructions in Section 3.4.

FP-524D-HRT Instruction Manual Rev. 0.1 Page 11 of 48

Model FP-524D-HRT

NOTE

: While in the Program Mode, if there is no magnetic switch interaction after 4

consecutive menu scrolls, the sensor will automatically revert to normal operating condition.

3. Operation

3.1 Programming Magnet Operating Instructions

The Operator Interface of the FP-524D-HRT Series gas sensors is accomplished via two internal magnetic
switches located above and below the LED display (Figure 13). The two switches, labeled “PGM1” and
“PGM2”, allow for complete calibration and configuration, thereby eliminating the need for area de­classification or the use of hot permits.

Figure 12 Magnetic Programming Tool

The magnetic programming tool (Figure 12) is used to operate the magnetic switches. Switch action is defined
as momentary contact, 3-second hold, and 10-second hold. (Hold times are defined as the time from the point

when the arrow prompt “▼” appears.) For momentary contact use, the programming magnet is briefly held

over a switch location. For 3-second hold, the programming magnet is held in place over the switch location
for three seconds. For 10-second hold, the programming magnet is held in place over the switch location for
10 seconds. The 3 and 10 second holds are generally used to enter calibration/program menus and save new
data. The momentary contact is generally used to move between menu items and to modify set-point values.

Arrows (“▼” and “▲”) are used on the LED display to indicate when the magnetic switches are activated.

The location of “PGM1” and “PGM2” are shown in Figure 13.

Program 1

PGM 1

MODEL FP-524D-HRT

HOUSTON,TEXAS

TM

MicroSafe LEL Gas Sensor

ALM ALM

FLT 1 2 CAL

PGM 2

Program 2

Figure 13 Magnetic Programming Switches

While changing values inside menu items, if there is no magnet activity after 3-4 seconds

the sensor will revert to the menu scroll.

(Exception to this is with “Signal Output Check” mode.)

FP-524D-HRT Instruction Manual Rev. 0.1 Page 12 of 48