Sperian Biosystems NXP Reference Manual
Biosystems
NXP
Fixed Gas
Detector Head
Reference
Manual
Sperian Instrumentation
651 South Main Street
Middletown, CT 06457
800-711-6776
860-344-1079
Fax 860-344-1068
Part Number 13-345
Version 1.01
10SEP2009
http://www.biosystems.com
2
THE BIOSYSTEMS NXP FIXED GAS DETECTOR HEAD HAS BEEN
DESIGNED FOR THE DETECTION AND MEASUREMENT OF
POTENTIALLY HAZARDOUS ATMOSPHERIC CONDITIONS.
IN ORDER TO ASSURE THAT THE USER IS PROPERLY WARNED
OF POTENTIALLY DANGEROUS ATMOSPHERIC CONDITIONS, IT
IS ESSENTIAL THAT THE INSTRUCTIONS IN THIS REFERENCE
MANUAL BE READ, FULLY UNDERSTOOD, AND FOLLOWED.
Biosystems NXP
Reference Manual
Sperian Instrumentation Part Number 13-345
Version 1.01
Copyright 2009
by
Sperian Protection Instrumentation, LLC
Middletown, Connecticut 06457
All rights reserved.
No page or part of this operation manual may be reproduced in any form without
written permission of the copyright owner shown above.
Sperian reserves the right to correct typographical errors.
Specifications are subject to change without notice.
1
Table of Contents
Signal Words .......................................................................................................................5
Modification of Sperian Instrumentation Products ...............................................................5
Operating Temperature and Humidity Limits .......................................................................5
Warnings and Cautions .......................................................................................................6
1. Overview.......................................................................................................................7
1.1 Capabilities ..........................................................................................................7
1.2 Method of sampling..............................................................................................7
1.3 Sensor options .....................................................................................................7
1.4 Verification of accuracy........................................................................................7
1.5 Displays and controls...........................................................................................8
1.6 Power requirements.............................................................................................8
1.7 Alarms and Alarm Logic.......................................................................................8
1.7.1 Atmospheric Hazard Alarms ............................................................................8
1.7.2 Sensor Over-range Alarms ..............................................................................9
1.7.3 Alarm Relays ..................................................................................................10
1.8 Fault Conditions .................................................................................................10
1.9 Remote Sensors ................................................................................................10
1.10 4-20 mA Current Loop .......................................................................................11
1.11 Event Logger......................................................................................................11
1.12 Firmware Upgrades............................................................................................11
2. Installation ..................................................................................................................12
2.1 Installation overview...........................................................................................12
2.2 Cautions.............................................................................................................13
2.3 NXP Detector Head Environmental Ratings ......................................................13
2.4 Siting of detector heads .....................................................................................13
2.5 Wiring requirements...........................................................................................13
2.5.1 Grounding ......................................................................................................14
2.6 Output Specifications .........................................................................................14
2.7 External Wiring...................................................................................................14
2.8 Remote Sensor Installation ................................................................................16
2.8.1 Disconnecting the sensor ...............................................................................16
2.8.2 Connecting the sensor cable..........................................................................16
2.8.3 Mounting the remote sensor ..........................................................................16
2.8.4 Connecting the cable (non-explosion-proof sensor) ......................................16
2.8.5 Connecting the cable (explosion-proof sensor)..............................................16
3. Field Usage ................................................................................................................18
2
3.1 Modes of operation ............................................................................................18
3.2 Clearing the MAX reading..................................................................................19
3.3 Effect of contaminants on NXP sensors.............................................................20
3.3.1 Effects of contaminants on oxygen sensors...................................................20
3.3.2 Effects of contaminants on combustible sensors ...........................................20
3.3.3 Effects of contaminants on toxic gas sensors ................................................20
3.4 Sensor Replacement .........................................................................................21
4. Verification of Accuracy (Calibration) .........................................................................22
4.1 Warnings and cautions concerning verification of accuracy ..............................22
4.2 Overview of verification of accuracy...................................................................22
4.2.1 Calibration Interval .........................................................................................22
4.2.2 Special Instructions for Fixed Gas Detectors .................................................22
4.2.3 Accuracy of Oxygen Sensors.........................................................................22
4.2.4 Accuracy of Toxic and LEL Sensors ..............................................................23
4.3 Fresh air calibration ...........................................................................................23
4.4 Span calibration of Toxic and LEL sensors........................................................24
4.5 Test Mode ..........................................................................................................25
4.6 Calibration Failures ............................................................................................26
4.6.1 Fresh Air Calibration Failure ..........................................................................26
4.6.2 Span Calibration Failure.................................................................................26
5. Configuration ..............................................................................................................28
5.1 Accessing the Setup menu and Submenus .......................................................28
5.2 Setup Submenu Flow Chart...............................................................................29
5.3 Set Date and Time .............................................................................................30
5.4 Set Loop Range .................................................................................................30
5.5 Set Alarm Levels................................................................................................30
5.6 Set Alarm Latch .................................................................................................31
5.7 Set Combustible Gas Sensor Display................................................................31
5.8 Set Cal Gas Concentration ................................................................................31
5.9 Set Cal Interval ..................................................................................................31
5.10 Set Bump Test Interval ......................................................................................31
6. Diagnostics .................................................................................................................32
6.1 Accessing the Diagnostics menu and Options...................................................32
6.2 Diagnostic Menu Flow Chart ..............................................................................33
6.3 Serial Number / Software Version......................................................................34
6.4 Sensor Count Display ........................................................................................34
6.5 Sensor Temperature Display .............................................................................34
3
6.6 Current Loop Output Test ..................................................................................34
6.7 Relay Test..........................................................................................................34
6.8 12-Volt Output Test............................................................................................35
6.9 LCD and Backlight Test .....................................................................................35
6.10 LED Test ............................................................................................................35
6.11 Audible Alarm Test.............................................................................................35
7. Service........................................................................................................................36
Returning your NXP to Sperian Instrumentation for service or repair ............................36
Appendices ........................................................................................................................37
Appendix A: NXP Toxic Sensor Cross Sensitivity Data .................................................37
Appendix B: Fault Conditions.........................................................................................38
Appendix C: Calibration Frequency Recommendation ..................................................39
Appendix D: Sperian Instrumentation Warranty Gas Detection Products......................40
4
Signal Words
The following signal words, as defined by ANSI Z535.4-1998, are used in the
NXP Reference Manual.
indicates an imminently hazardous situation which, if not
avoided, will result in death or serious injury.
indicates a potentially hazardous situation which, if not
avoided, could result in death or serious injury.
indicates a potentially hazardous situation, which if not avoided,
may result in moderate or minor injury.
CAUTION used without the safety alert symbol indicates a potentially
hazardous situation, which, if not avoided, may result in property damage.
The NXP MUST be installed in a non-hazardous area.
Modification of Sperian Instrumentation Products
Any unauthorized modification of any Sperian Instrumentation
product may compromise the certification and the safety of the product, and may
lead to serious personal injury or death. Modification of any part or component of a
Sperian Instrumentation product requires the express written approval of both the
appropriate certification agency and Sperian Instrumentation.
Operating Temperature and Humidity Limits
The Biosystems NXP’s operating temperature range is printed
on the label on the inside of the instrument. The Biosystems XPR’s operating
temperature range is printed on the housing. Use of Sperian Gas Detection
products outside of their specified operating temperature ranges may result in
inaccurate and potentially dangerous readings.
5
Warnings and Cautions
1. The Biosystems NXP gas detector has been designed for
the detection of dangerous atmospheric conditions. An alarm condition
indicates the presence of a potentially life-threatening hazard and should be
taken very seriously.
2.
In the event of an alarm condition it is important to follow
established procedures. The safest course of action is to immediately leave the
affected area, and to return only after further testing determines that the area is
once again safe for entry. Failure to immediately leave the area may result in
serious injury or death.
3.
The accuracy of the NXP should be checked periodically
with known concentration calibration gas. Failure to check accuracy can lead to
inaccurate and potentially dangerous readings.
4.
Fresh air/zero calibrations may only be performed in an
atmosphere that is known to contain 20.9% oxygen, 0% LEL and 0 PPM toxic
gas. If fresh air is unavailable, a cylinder of “Zero Air” must be used during the
fresh air/zero calibration procedure. Calibration of the NXP in a contaminated
atmosphere may lead to inaccurate and potentially dangerous readings.
5.
The accuracy of the NXP should be checked immediately
following any known exposure to contaminants by testing with known
concentration test gas before further use. Failure to check accuracy can lead to
inaccurate and potentially dangerous readings.
6.
A sensor that cannot be calibrated or is found to be out of
tolerance should be replaced immediately. An instrument that fails calibration
may not be used until testing with known concentration test gas determines that
accuracy has been restored, and the instrument is once again fit for use.
7.
Do not reset the calibration gas concentration unless you
are using a calibration gas concentration that differs from the one that is normally
supplied by Sperian for use in calibrating the NXP. Customers are strongly urged
to use only Sperian calibration materials when calibrating the NXP. Use of nonstandard calibration gas and/or calibration kit components when calibrating the
NXP can lead to inaccurate and potentially dangerous readings and may void
the standard Sperian warranty.
Sperian offers calibration kits and long-lasting cylinders of test gas
specifically developed for easy NXP calibration. Customers are strongly urged
to use only Sperian calibration materials when calibrating the NXP.
8.
For safety reasons this equipment must be operated and
serviced by qualified personnel only. Read and understand this reference
manual before operating or servicing the NXP.
9.
A rapid up-scale reading followed by a declining or erratic
reading may indicate a hazardous combustible gas concentration that exceeds
the XPR’s zero to 100 percent LEL detection range.
6
1. Overview
1.1 Capabilities
The NXP Gas Detector Head is a fixed
gas detection system from Sperian
Instrumentation. The NXP can function
on its own as a stand-alone unit, and can
also be used as part of a 4-20 mA current
loop system with a PLC or other type of
controller.
Standard features include user interface,
built-in digital readout to allow for direct
calibration at the head, and relays to allow
for additional alarms and control.
Each NXP Gas Detector Head includes a
sensor housing and gas-specific sensor.
Sensor housings are available in nonexplosion-proof and remote explosionproof (XPR) versions. Sensors can be
mounted directly to the NXP housing, or
can be placed remotely (up to 50 feet
away) using a special remote sensor
cable.
Note: Conduit, wire and other
components necessary to connect the
NXP Gas Detector Head to a controller
are not included and must be ordered
separately.
Installation of
explosion-proof housings must be
performed in accordance with local
regulations.
1.2 Method of sampling
The atmosphere being measured reaches
the sensor in the NXP/XPR by diffusing
through a protective filter directly into the
sensor. Normal air movements are
usually enough to carry the sample to the
sensor. The sensor reacts to changes in
the concentration of the hazard being
measured. Values are constantly updated
and displayed on the NXP Gas Detector
head’s LCD readout. If the head is
connected to a controller, the appropriate
level 4-20 mA signal is simultaneously
sent to the controller.
The NXP Gas Detector head may be
installed at a substantial distance from the
controller. The maximum distance
between the head and the controller is
2000 feet when using the proper cable.
Wiring requirements are discussed in detail
in section 2.5.
1.3 Sensor options
NXP Gas Detector Heads can be
configured to detect a number of different
atmospheric hazards. Each NXP uses a
single substance-specific sensor that
determines the hazard that the system is
configured to detect. The sensors that are
currently available, along with their ranges
and resolutions, are shown in table 1.3.
Note: Changing the sensor range will
require calibration of the instrument.
Sensor Range Resolution
Oxygen (O2)
Combustible
(LEL sensor)
Carbon
Monoxide
(CO)
Carbon
Monoxide
(CO-H)
Hydrogen
Sulfide (H
Hydrogen
Sulfide (H
Sulfur
Dioxide
(SO
)
2
0-25%/Vol.
0-30%/Vol.
0-100% LEL
0-5.0% CH
0-100 PPM
0-500 PPM
0-1000 PPM
0-100 PPM
0-500 PPM
0-1000 PPM
0-10 PPM 0.1 PPM
S)
2
0-50 PPM
0-100 PPM
S)
2
0-250 PPM
0-25 PPM
0-50 PPM
4
0.1% Vol
1% LEL
0.05% CH
1 PPM
1 PPM
1 PPM
0.1 PPM
Table 1.3 – Sensor Ranges
1.4 Verification of accuracy
NXP Gas Detector Heads have been
designed for easy verification of accuracy.
The accuracy of the NXP
should be checked periodically with
known concentration calibration gas.
Failure to check accuracy can lead to
inaccurate and potentially dangerous
readings.
Please see Sperian’s calibration
recommendations in Appendix C.
Verification of detector accuracy is a twostep procedure for toxic and LEL (XPR
only) sensor-equipped detectors, and a
one-step procedure for oxygen sensorequipped detectors.
Verification normally begins by exposing
the NXP’s sensor to known “fresh air” and
7
4
checking the readings. If the readings
differ from those expected in fresh air
(20.9% oxygen, 0 PPM toxic gas, 0% LEL
combustible gas), a "fresh air zero"
adjustment must be made. For most fixed
applications, where the freshness of the
ambient air is in question, a cylinder of
“Zero Air” must be used during the fresh
air/zero calibration.
The second step, which only applies to
toxic and LEL sensors, is to verify sensor
accuracy by exposing it to known
concentration test gas and noting the
response. Toxic and LEL readings are
considered accurate if the readings are
between 90% and 120% of the expected
value as given on the gas cylinder. If the
reading is accurate, then the instrument
requires no further adjustment. Toxic and
LEL readings that fall outside of this range
are considered inaccurate and indicate
that the sensor must be calibrated before
further use.
Calibration procedures are discussed
in detail in Chapter 4.
1.5 Displays and controls
NXP Gas Detector Heads include a 3-digit
LCD located on the face of the detector
housing. The heads also include a MODE
button that allows the user to initiate and
control the calibration of the detector.
1.6 Power requirements
Power to the NXP can be provided either
from a controller or via a standard wall cube
available from Sperian.
The NXP requires a power supply of 13-30
VDC. Power is applied to connector J1 (see
Figure 2.5). Once powered up and running,
the NXP is intended for continuous
monitoring. If it is necessary to power down
the NXP, power should be removed from
the wall cube or controller that is supplying
power to the NXP.
1.7 Alarms and Alarm Logic
NXP Gas Detector
Heads have been designed for the
detection of dangerous atmospheric
conditions. An alarm condition
indicates the presence of a potentially
life-threatening hazard and should be
taken very seriously.
In the event of an alarm condition it is
important to follow established
procedures. The safest course of action
is to immediately leave the affected area,
and return only after further testing
together with other appropriate safety
procedures determine that the area is
once again safe for entry.
1.7.1 Atmospheric Hazard Alarms
NXP Fixed Gas Detectors with toxic or
combustible gas sensors include two levels
of alarms. One alarm serves as the
warning alarm; the second alarm serves as
the danger alarm. Detectors with oxygen
sensors have four alarm levels, as
described below.
Figure 1.5 – Main NXP Components
Toxic and combustible gas sensors have
“ascending” alarms, meaning that the
alarms are activated when gas readings
rise above a pre-set alarm threshold.
Oxygen sensors have both “ascending” and
“descending” alarms, meaning that the
alarms activate when gas readings rise
above a pre-set alarm threshold or fall
below a pre-set alarm threshold. There is a
warning alarm and a danger alarm in each
direction.
Table 1.7 lists the available alarm levels
and span gas values for each sensor type.
Custom alarm levels and calibration gas
values may be set using BioTrak II
8
software. Please see the BioTrak II
operation manual for instructions. The
alarm levels apply to both warning and
danger alarms, with the following
restrictions:
• Alarms can not be set to a value
above the full-scale range. If a range
is selected that is below current alarm
levels, the alarms will be adjusted to
default values for that range.
• The warning alarm can not be set
beyond the danger alarm setting.
Sensor
Available Alarm Levels
Type
(Process) High: OFF, 1.0, 2.0, 2.5, 5%
Oxygen (O2)
Combustible
(LEL display)
Combustible
display)
(CH
4
Carbon
monoxide
(CO, CO-H)
Hydrogen
sulfide (H
Sulfur Dioxide
(SO
S)
2
)
2
(Safety) High: 22.0, 22.5, 23.0, 23.5%
(Safety) Low: 20.0, 19.5, 19.0, 18.5, 18.0%
OFF, 0.25, 0.5, 0.75, 1.0, 1.25, 2.5% CH
OFF, 10, 25, 35, 50, 100, 150, 200 PPM
(Process) Low: OFF
OFF, 5, 10, 15, 20, 25, 50% LEL
OFF, 2, 5, 10, 15, 20 PPM
OFF, 2, 5, 10, 15, 20 PPM
Table 1.7 – Available alarm levels and calibration span gas settings
When an alarm set point is exceeded the
LEDs on the front panel and in the strobe
housing will flash (Yellow for Warning, Red
for Danger), and the audible alarm will
sound. Any external devices controlled by
means of the NXP’s alarm relay contacts
will also be activated.
Latching Alarms
NXP alarms are normally self-resetting.
When readings drop back below the preset alarm levels, the instrument returns to
normal operation, and the alarms and relay
contacts are turned off.
It is possible to set NXP’s alarms so that
they "latch". During latched operation,
once an alarm condition occurs, the visual
and audible alarms and relays will remain
active even after the atmospheric hazard
has cleared. They must be manually reset
using the MODE button. See section 5.6
for information on setting latching alarms.
Available
Span Gas
Settings
N/A
25, 30, 40, 50,
60% LEL
4
1.25, 1.5, 2.0, 2.5,
3.0% CH
35, 50, 75, 100,
150, 200 PPM
10, 20, 25, 30
PPM
10, 20, 25, 30
PPM
4
Alarm Acknowledgement
During an alarm condition, the audible
alarm and the strobe LEDs can be
acknowledged (temporarily deactivated) by
pressing the MODE button. The LEDs on
the display board and the alarm relays will
remain active. Once acknowledged, the
audible alarm and strobe LEDs will be
reactivated under the following conditions:
• Gas level remains above the alarm
level for 5 minutes
• Gas level decreases below the alarm
level, and then rises above it again
• Warning alarm was acknowledged, and
the gas level then rises above the
Danger alarm level
1.7.2 Sensor Over-range Alarms
If the concentration of the gas being
detected goes above the selected sensor
range, a sensor over-range occurs.
9
The instrument will act as if a danger alarm
condition exists, even if the alarms have
been disabled.
• Oxygen and Toxic Gas Over-range
When the gas concentration falls back
within the sensor’s range, the over-range
alarm will be reset, unless latching alarms
have been selected.
• Combustible Gas Over-range
In the case of an LEL over-range condition
(LEL over 100%), power to the LEL sensor
will be disconnected to protect the sensor
from overheating and premature failure.
The instrument will remain in alarm with
the sensor powered down until the MODE
button is pressed or the instrument’s power
is cycled.
If the MODE button is pressed during this
time, power to the sensor will be turned on
briefly. If the gas level is below 100% LEL,
the sensor will remain on and the
instrument will resume gas detection
mode, along with any applicable alarms. If
the gas level is still over 100% LEL, the
sensor will be shut off again and the
instrument will remain in over-range alarm.
1.7.3 Alarm Relays
The NXP incorporates relays that are
activated during alarm conditions. There
are separate relays for Warning and
Danger alarms, as well as a Fault condition
relay (see section 1.8).
The Warning and Danger relays are
activated any time that the gas level
exceeds the current alarm levels. Each
relay has a normally-open and a normallyclosed contact. Normally-open contacts
close (make contact) during an alarm
condition, while normally-closed contacts
open (break contact).
These contacts can be used to operate
external alarms or larger relays that drive
other equipment, such as ventilation
systems. See Figure 2.5 for relay
connection locations.
The relay contacts in the NXP do not
supply power to the external accessories.
They act as switch contacts only. External
alarms, relays and contactors require their
own power supplies.
The maximum rating of the NXP’s relay
contacts is 30 VDC at 5 amps.
Under no
circumstances should AC line voltage
be connected directly to the relay
contacts.
1.8 Fault Conditions
The NXP is capable of detecting certain
internal fault conditions. During one of
these conditions the loop current will fall to
2 mA, the Fault relay will be activated, and
the red LEDs will flash every 5 seconds to
alert the user to the problem. Fault codes
are listed below. See Appendix B for
explanations of fault codes.
F1 - Sensor Fault
F2 – EEPROM Read Fault
F5 – EEPROM Write Fault
F11 – Power Low Fault
F12 – Power High Fault
Power Failure Fault
The Fault relay is normally energized. This
is called Fail-Safe mode. In the case of a
total loss of power to the instrument, the
Fault relay will trip, and any external
devices connected to it will be activated.
Loop current will fall to 0 mA.
Note: The Fault relay does not supply
power to the device(s) connected to it. It
acts as a switch contact only. External
power must be supplied to any devices
connected to this relay.
Under no
circumstances should AC line voltage
be connected directly to the relay
contacts.
1.9 Remote Sensors
The NXP normally comes with the sensor
housing attached to the instrument. When
necessary, the sensor can be installed
remotely, up to 50 feet from the instrument.
10
The standard sensor can be used for nonhazardous (non-explosive) environments.
For use in hazardous locations, the XPR
explosion-proof sensor housing must be
used. The XPR is built into a heavy-duty
stainless steel explosion-proof housing. See
section 2.8 for remote sensor installation.
The XPR remote
sensor housing must not
be opened in
a hazardous location unless power to
the NXP has been disconnected. Power
must not be restored to the NXP until
the XPR housing has been completely
closed.
Installation of
explosion-proof housings must be
performed in accordance with local
regulations.
1.10 4-20 mA Current Loop
The NXP incorporates a connection for an
industry-standard 4-20 mA current loop.
This circuit generates a current based on
the gas level detected. The NXP is
normally set to “Source” mode, meaning
that it generates a current output. It can
also be set to “Sink” mode if needed,
meaning that it sinks (inputs) the current
from an external source.
A 4 mA signal indicates a reading of zero,
and a 20 mA signal indicates a full-scale
reading. Full-scale is determined by the
Loop Range setting in the Setup menu.
See Table 1.3 for available ranges and
section 5.4 for instructions on setting the
Loop Range. See Figure 2.5 for wiring of
the loop signal.
1.11 Event Logger
The event logger in the NXP stores data
associated with alarm conditions. Each
event (alarm) includes the following data:
• Event Start time
• Event End time
• Duration of the event.
• Minimum reading during event
• Maximum reading during event
• Average reading during event
• Temperature at end of event
• Sensor type
• Flags for ‘In calibration’, warning alarm,
danger alarm and temperature alarm
during event
• Time event was acknowledged
The NXP stores the data from the 128
most recent alarm events. Once 128
events have been stored, the NXP will
begin to overwrite the data from the oldest
event in memory with data from new
events. One event may be a combination
of different alarms occurring
simultaneously or in immediate
succession.
The event logger may be downloaded
using BioTrak II software. The PC must be
equipped with an IrDA port to provide a
connection.
While the NXP is
communicating through its IrDA
connection, it IS NOT
sensing the gas
level of the atmosphere, and WILL NOT
activate any alarms. The area must be
made safe or another form of
atmospheric monitoring must be used
during IrDA communication.
1.12 Firmware Upgrades
As improvements are made and features
are added to the NXP’s firmware, new
versions of the firmware will be made
available to customers. Normally, this
firmware can be downloaded and installed
by the customer using a computer with
IrDA communication capability and the
FX2 Flash Upgrade utility software.
Instrument firmware and upgrade utility
software can be downloaded from
http://www.biodownloads.com
in the
Download Section.
11
Loading...