Title: Ultima
1Ultima MOS-5 Hydrogen Sulfide Intelligent Sensor
Introduction to a HART Enabled Detector for
Hydrogen Sulfide Gas Detection
EVERY LIFE HAS A PURPOSE
2Contents
- Product Overview
- Detector Placement
- Wiring
- Gas Check
- Calibration
- Fault Conditions
- HART
- Applications
- Conclusion
- Appendix
3Ultima MOS-5 Intelligent Sensor
- Description
- Intelligent hydrogen sulfide (H2S) sensor that
supports HART communication - Like other HART equipment, uses existing 4-20 mA
wiring and reduces installation costs - Customer Benefits
- Better diagnostics
- Improved management of maintenance history and
event log - ModBus data block transfer
4New Features
- HART
- Two-way digital communication using existing
wiring - Event logging
- Store up to ten events each of warning and alarm
events, calibrations and cal checks, and faults - Dual simultaneous block transfer ModBus
- Receive up to 100 values with one request
- Other features
- Better protection against wiring misuse
- New microprocessor and components
5 Ultima MOS-5 Intelligent Sensor at a Glance
Description Ultima MOS-5
Sensor life (yrs) 3-5 years
Repeatability 2 ppm or 10 of applied gas
Response Time, T50 lt 1 minute (screen)
Regulatory Approvals ATEX, CE, CSA, FM
Digital Communication HART, ModBus
Operating Temperature Range -40 to 75C
Storage Temperature Range -50 to 85C
Operating Humidity 5 to 100 RH, non-condensing
Input Power 20 to 36 VDC
SIL Suitability 2 or 3
The 4-20 mA output has a higher safety rating
than relay outputs.
6Sensor Placement
- Location and quantity of Ultima MOS-5 Sensors
depend on several factors1, 2 - Potential for personnel exposure
- Density of hydrogen sulfide
- Air velocity and direction of gas dispersion
- Location and nature of potential leak sources
(eg. pressure, amount, source temperature,
distance) - Accessibility to the detection instruments
- Ambient temperature and vibration
- Affect of structural arrangements (eg. walls,
troughs, partitions) on gas accumulations - Mechanical damage and contamination
- Possible sources of electromagnetic or radio
interference
1 ISA-RP92.0.02, Part II-1998, Installation,
Operation, and Maintenance of Toxic Gas-Detection
Instruments Hydrogen Sulfide, April 15,
1998. 2 Environmental, Health, and Safety
Guidelines for Offshore Oil and Gas Development,
International Finance Corporation, April 30, 2007.
7Sensor Placement (Continued)
- Industry organizations like the American
Petroleum Institute recommend specific sensor
locations, alarm settings, and maintenance
cycles1
Location Alarm Settings Maintenance Cycle
Bell nipple Mud-return line receiver tank and shale shaker Pipe-trip tank Well-control fluid pit area Drillers or operators station Living quarters, if located close to well Low alarm 10 ppm High alarm 300 pm Service, testing, and calibration as recommended by manufacturer
1 API RP 49, Recommended Practice for Drilling
and Well Servicing Operations Involving Hydrogen
Sulfide, 3rd Edition, May 2001, reaffirmed March
2007.
8Gas Check
- The Ultima MOS-5 gas check procedure
- To enter gas check mode, do one of the following
- Place magnet over MSA logo and hold until
flashing - - appears on display - Send HART command or ModBus register
- Apply hydrogen sulfide
- When reading has stabilized, remove gas and the
unit will return to normal operation
9Calibration
- The Ultima MOS-5 calibration is performed as
follows - To enter calibration mode, do one of the
following - Place magnet over MSA logo and hold until AC
appears on display - Send HART command or ModBus register
- Select calibration life
- Apply calibration gas display changes from AC
to CP - After few minutes, display changes from CP to
CC - When gas is removed, reading returns to 0
10Fault Conditions
- The Ultima MOS-5 Intelligent Sensor has
self-diagnostics that inform users when certain
types of device failures have occurred - If a fault is detected, the output signal
decreases, the fault relay de-energizes, and one
of the following fault codes is displayed
Fault Code Description
F2 Failed to complete calibration
F3 Flash checksum error
F4 Sensor heater open error or sensor amplifier error
F5 Sensor heater shorted
F6 Low supply voltage
F7 EEPROM verification failure
F8 Failure to complete setup
F9 Gas check period exceeded
F10 Switch error
F11 Internal error
11HART
Function Current Level (mA) Current Level (mA) Current Level (mA)
Function Analog Output (Standard) Modbus HART modified Analog Output
Startup 4.05 4.05 4.05
Zero reading 4.05 4.05 4.05
Fault 0 0 1.25
Gas check 1.5 1.5 1.5
Calibrate 1.5 1.5 1.5
Gas 4 - 20 4 - 20 4 - 20
Overrange 20 - 22 20 - 22 20 21.7
- An expanded scale HART configuration offers a
minimum current of 1.25 mA to match current
settings for many controllers and PLCs
12Uses of HART and ModBus
- Asset management and process improvement
- Check compliance to calibration schedule
- Coordinate calibrations so as to reduce labor
cost - Aggregate calibration to a control room
anywhere in the world - Track gas concentration remotely
- Read fault conditions from control room before
sending technician to the field - Obtain readout of voltage at end of wire
- Installation
- Set up Ultima MOS-5 Intelligent Sensor easily
without magnet
13Applications
- The Ultima MOS-5 Intelligent Sensor is well
suited for monitoring the extraction, transport,
storage, and processing of sour oil and natural
gas - Common applications
- Gas compressor stations
- Pipelines
- Gas turbine power plants
- Oil and gas terminals
- Refineries
- Oil and gas storage tanks
- Oil and gas platforms
14Conclusion
- The Ultima MOS-5 is a new hydrogen sulfide gas
detector that improves plant safety - Reduces maintenance costs
- Enhances management of maintenance history and
fault records through HART and ModBus - When used with ModBus, block transfer enables
fast delivery of large quantities of data - Allocation and placement of the detector follows
common industry practice - Potential for personnel exposure, location and
nature of the gas leak, and direction of gas
dispersal are a few of several important
considerations
15Conclusion (Continued)
- HART and ModBus communications allow users to get
the full benefit from the Ultima MOS-5
Intelligent Sensor - Real time device diagnostics enable proactive
action to avoid process disruptions and unplanned
shutdowns - The Ultima MOS-5 is a versatile detector, with
broad application to the oil and gas, chemical
process, and other industries
16Appendix
17Cross Sensitivity1
Description Applied ppm MSA Icare1 Detcon2
Methane 20,000 0 0 0
Propane 20,000 0 2 0
Pentane 20,000 0 2 0
Hexane 20,000 0 4 0
Ethylene 20,000 0 6 0
Propylene 20,000 0 11 5
Ethylene oxide 20,000 0 7 0
Propylene oxide 2,000 0 16 0
Methanol 20,000 0 gt 50 gt 50
Methanol 2,000 0 24 15
Ethanol 20,000 0 gt 50 gt 50
Ethanol 2,000 0 21 7
1 Icare model DMITT63. 2 Detcon model TP-524.
18Cross Sensitivity (Continued)
Description Applied ppm MSA Icare Detcon
Isopropanol 20,000 0 gt 50 0
Isopropanol 2,000 0 20 0
Butanol 20,000 0 gt 50 3
Butanol 2,000 0 45 2
Acetone 20,000 0 gt 50 17
Acetone 2,000 0 16 0
Hydrogen 20,000 0 gt 50 gt 50
Hydrogen 500 0 16 24
Hydrogen 200 0 7 4
Ammonia 500 0 8 6
Carbon monoxide 20,000 0 3 0
Sulfur dioxide 10,000 0 2 0