WatchGas SST1 Serviceable SO2 Gas Detector SST1-S
Description
You'll smell sulfur dioxide before you can see it — but by the time you're smelling it, you may already be at OSHA's permissible exposure limit.
SO2 has a pungent, unmistakable odor that most workers can detect between 0.5 and 3 ppm. That's the problem: OSHA's permissible exposure limit is 5 ppm as an 8-hour time-weighted average, and NIOSH's more conservative recommended limit is 2 ppm TWA with a 5 ppm short-term exposure limit. The concentration where you can smell SO2 and the concentration where you're already over the exposure limit overlap. Smell isn't a reliable measure of what you're breathing.
The WatchGas SST1-S Serviceable SO2 Gas Detector gives you a number instead of a nose.
It reads sulfur dioxide continuously in ppm across a 0–100 ppm range — spanning OSHA's PEL of 5 ppm through the NIOSH IDLH threshold of 100 ppm. Default alarm setpoints ship at Low 2 ppm (matching the NIOSH REL TWA) and High 5 ppm (matching OSHA's PEL and the NIOSH REL STEL). Configurable low, high, TWA, and STEL alarms let you tune the monitor to whichever standard your facility runs against — OSHA, NIOSH, ACGIH, or a stricter internal program.
Why refinery operators, mill supervisors, and smelter safety managers pick the SST1 line:
- Continuous SO2 monitoring in ppm with configurable Low, High, TWA, and STEL alarms — ship defaults already aligned to NIOSH REL
- Serviceable sensor — replace the SO2 sensor cell instead of the whole unit at end-of-life
- 3-year instrument warranty (vs. the industry-typical 2 years) with a 2-year sensor warranty
- 3-year replaceable battery based on typical alarm exposure
- Solid polymer sensor technology — compact, robust, temperature-tolerant
- NFC configuration and WatchGas App integration for datalogging
- Vibration + audible + visual alarms — you notice it on the operating floor or the boiler deck
- Bump test and calibration compatible with the
WatchGas SST-DOCK; compliance check-in compatible with the
WatchGas SST-KIOSK
Sensor and alarm specifications:
Sensor
Gas measuring range
Low alarm (default)
High alarm (default)
SO2
0 – 100 ppm
2 ppm
5 ppm
PK Safety services the full WatchGas SST line with factory-trained technicians in-house. We also handle BW/Honeywell (Factory Authorized Service Center), RKI, and RAE Systems monitors — one shop for a mixed-brand fleet. When the SO2 sensor drifts or needs replacement, send the unit to us — you're not shipping equipment into a black box. Call us at
800.829.9580 to talk through your sulfur dioxide monitoring setup with someone who understands SO2 detection and the WatchGas SST platform.
This is right for you if:
- You work in petroleum refining — sour crude handling, hydrotreating, sulfur recovery units
- You operate in pulp and paper — Kraft process, black liquor recovery, on-site sulfur recovery
- You supervise a steel plant, metal smelting operation (copper, zinc, lead), or sulfuric acid facility
- You run boilers, coal-fired power generation, or industrial combustion equipment where SO2 is present in flue gas
- You work in mining or mineral processing with sulfide ore roasting or smelting
- You need continuous SO2 exposure logs for OSHA respiratory protection compliance, EPA emissions monitoring, or internal safety audits
Technical documents:
Brochure
Specification Sheet
Quick Start Guide
Part Number: WG01-SST1-S — SST1-S Serviceable SO2 (Sulfur Dioxide) Gas Detector, 0–100 ppm range, real-time display
Frequently Asked Questions
What is the OSHA exposure limit for sulfur dioxide?
OSHA's permissible exposure limit (PEL) for sulfur dioxide is 5 ppm as an 8-hour time-weighted average, under 29 CFR 1910.1000 Table Z-1. NIOSH's recommended exposure limit (REL) is more conservative at 2 ppm TWA plus a 5 ppm short-term exposure limit (STEL) over any 15-minute period. ACGIH sets an even stricter TLV-STEL of 0.25 ppm, which some industrial safety programs use as an internal target.
The SST1-S ships with default alarm setpoints of Low 2 ppm and High 5 ppm — already aligned to the NIOSH REL. Configurable low, high, TWA, and STEL alarms let you tune the monitor to your facility's exposure program (OSHA, NIOSH, ACGIH, or a stricter internal standard).
Which industries typically require sulfur dioxide monitoring?
SO2 monitoring is a compliance requirement or best practice across a range of settings: petroleum refining (sour crude processing, hydrotreating, sulfur recovery units), pulp and paper (Kraft process, black liquor recovery, on-site sulfur recovery), metal smelting operations (copper, zinc, lead sulfide ore processing), sulfuric acid manufacturing, coal-fired power generation, industrial boilers and combustion equipment, and mining and mineral processing.
Any workplace where SO2 is produced or handled also falls under OSHA's respiratory protection standard (29 CFR 1910.134). Facilities in populated areas may additionally have EPA ambient-air and emissions-monitoring obligations under the Clean Air Act.
Can I detect SO2 by smell instead of using a monitor?
Not reliably. Sulfur dioxide has a pungent, sharp odor most workers can detect between 0.5 and 3 ppm — but that range overlaps with OSHA's exposure limit of 5 ppm. Individual odor detection thresholds vary widely, and chronic exposure can dull the sensation. Some workers smell SO2 well below the exposure limit; others don't notice it until they're already above it.
A continuous readout in ppm from the SST1-S shows the actual concentration regardless of nose sensitivity — and produces the audit-ready exposure log that compliance programs and internal safety reviews need.
What does "serviceable" mean on the SST1-S?
Traditional single-gas monitors are single-use — when the sensor reaches end-of-life (typically 2–3 years), the whole unit gets replaced. The SST1 platform is designed to be serviced: the SO2 sensor cell can be replaced, extending the monitor's service life beyond the sensor's own lifespan. Instrument warranty is 3 years; sensor warranty is 2 years. PK Safety services the WatchGas SST line in-house — send the unit in when the sensor needs replacement.
Does the SST1-S work with the WatchGas SST-DOCK and SST-KIOSK?
Yes to both. The SST1-S is fully compatible with the
WatchGas SST-DOCK Touchscreen docking station for automatic bump testing, calibration, and datalogging (about 60 seconds per unit), and with the
WatchGas SST-KIOSK compliance kiosk for fleet-level compliance check-in, alarm history upload, and user/location tracking.
If you're running a fleet of SST1 monitors across a refinery, mill, or smelter, the SST-DOCK + SST-KIOSK combination covers your bump/cal workflow and your compliance-tracking workflow together.
How does PK Safety support the SST1-S after purchase?
PK Safety carries the full WatchGas SST line and services the SST1-S with factory-trained technicians in-house. That includes SO2 sensor replacement when the cell reaches end-of-life, calibration, firmware updates, and warranty support (3-year instrument warranty, 2-year sensor warranty). Call
800.829.9580 to talk through your sulfur dioxide monitoring setup with someone who knows the SST1 platform — not a call-center script.
Not sure this is the right fit? Call PK Safety at 800.829.9580. A person who knows sulfur dioxide monitoring and the WatchGas SST platform will pick up.
Read more
Description
You'll smell sulfur dioxide before you can see it — but by the time you're smelling it, you may already be at OSHA's permissible exposure limit.
SO2 has a pungent, unmistakable odor that most workers can detect between 0.5 and 3 ppm. That's the problem: OSHA's permissible exposure limit is 5 ppm as an 8-hour time-weighted average, and NIOSH's more conservative recommended limit is 2 ppm TWA with a 5 ppm short-term exposure limit. The concentration where you can smell SO2 and the concentration where you're already over the exposure limit overlap. Smell isn't a reliable measure of what you're breathing.
The WatchGas SST1-S Serviceable SO2 Gas Detector gives you a number instead of a nose.
It reads sulfur dioxide continuously in ppm across a 0–100 ppm range — spanning OSHA's PEL of 5 ppm through the NIOSH IDLH threshold of 100 ppm. Default alarm setpoints ship at Low 2 ppm (matching the NIOSH REL TWA) and High 5 ppm (matching OSHA's PEL and the NIOSH REL STEL). Configurable low, high, TWA, and STEL alarms let you tune the monitor to whichever standard your facility runs against — OSHA, NIOSH, ACGIH, or a stricter internal program.
Why refinery operators, mill supervisors, and smelter safety managers pick the SST1 line:
- Continuous SO2 monitoring in ppm with configurable Low, High, TWA, and STEL alarms — ship defaults already aligned to NIOSH REL
- Serviceable sensor — replace the SO2 sensor cell instead of the whole unit at end-of-life
- 3-year instrument warranty (vs. the industry-typical 2 years) with a 2-year sensor warranty
- 3-year replaceable battery based on typical alarm exposure
- Solid polymer sensor technology — compact, robust, temperature-tolerant
- NFC configuration and WatchGas App integration for datalogging
- Vibration + audible + visual alarms — you notice it on the operating floor or the boiler deck
- Bump test and calibration compatible with the WatchGas SST-DOCK; compliance check-in compatible with the WatchGas SST-KIOSK
Sensor and alarm specifications:
| Sensor | Gas measuring range | Low alarm (default) | High alarm (default) |
| SO2 | 0 – 100 ppm | 2 ppm | 5 ppm |
PK Safety services the full WatchGas SST line with factory-trained technicians in-house. We also handle BW/Honeywell (Factory Authorized Service Center), RKI, and RAE Systems monitors — one shop for a mixed-brand fleet. When the SO2 sensor drifts or needs replacement, send the unit to us — you're not shipping equipment into a black box. Call us at 800.829.9580 to talk through your sulfur dioxide monitoring setup with someone who understands SO2 detection and the WatchGas SST platform.
This is right for you if:
- You work in petroleum refining — sour crude handling, hydrotreating, sulfur recovery units
- You operate in pulp and paper — Kraft process, black liquor recovery, on-site sulfur recovery
- You supervise a steel plant, metal smelting operation (copper, zinc, lead), or sulfuric acid facility
- You run boilers, coal-fired power generation, or industrial combustion equipment where SO2 is present in flue gas
- You work in mining or mineral processing with sulfide ore roasting or smelting
- You need continuous SO2 exposure logs for OSHA respiratory protection compliance, EPA emissions monitoring, or internal safety audits
Technical documents:
Brochure
Specification Sheet
Quick Start Guide
Part Number: WG01-SST1-S — SST1-S Serviceable SO2 (Sulfur Dioxide) Gas Detector, 0–100 ppm range, real-time display
Frequently Asked Questions
What is the OSHA exposure limit for sulfur dioxide?
OSHA's permissible exposure limit (PEL) for sulfur dioxide is 5 ppm as an 8-hour time-weighted average, under 29 CFR 1910.1000 Table Z-1. NIOSH's recommended exposure limit (REL) is more conservative at 2 ppm TWA plus a 5 ppm short-term exposure limit (STEL) over any 15-minute period. ACGIH sets an even stricter TLV-STEL of 0.25 ppm, which some industrial safety programs use as an internal target.
The SST1-S ships with default alarm setpoints of Low 2 ppm and High 5 ppm — already aligned to the NIOSH REL. Configurable low, high, TWA, and STEL alarms let you tune the monitor to your facility's exposure program (OSHA, NIOSH, ACGIH, or a stricter internal standard).
Which industries typically require sulfur dioxide monitoring?
SO2 monitoring is a compliance requirement or best practice across a range of settings: petroleum refining (sour crude processing, hydrotreating, sulfur recovery units), pulp and paper (Kraft process, black liquor recovery, on-site sulfur recovery), metal smelting operations (copper, zinc, lead sulfide ore processing), sulfuric acid manufacturing, coal-fired power generation, industrial boilers and combustion equipment, and mining and mineral processing.
Any workplace where SO2 is produced or handled also falls under OSHA's respiratory protection standard (29 CFR 1910.134). Facilities in populated areas may additionally have EPA ambient-air and emissions-monitoring obligations under the Clean Air Act.
Can I detect SO2 by smell instead of using a monitor?
Not reliably. Sulfur dioxide has a pungent, sharp odor most workers can detect between 0.5 and 3 ppm — but that range overlaps with OSHA's exposure limit of 5 ppm. Individual odor detection thresholds vary widely, and chronic exposure can dull the sensation. Some workers smell SO2 well below the exposure limit; others don't notice it until they're already above it.
A continuous readout in ppm from the SST1-S shows the actual concentration regardless of nose sensitivity — and produces the audit-ready exposure log that compliance programs and internal safety reviews need.
What does "serviceable" mean on the SST1-S?
Traditional single-gas monitors are single-use — when the sensor reaches end-of-life (typically 2–3 years), the whole unit gets replaced. The SST1 platform is designed to be serviced: the SO2 sensor cell can be replaced, extending the monitor's service life beyond the sensor's own lifespan. Instrument warranty is 3 years; sensor warranty is 2 years. PK Safety services the WatchGas SST line in-house — send the unit in when the sensor needs replacement.
Does the SST1-S work with the WatchGas SST-DOCK and SST-KIOSK?
Yes to both. The SST1-S is fully compatible with the WatchGas SST-DOCK Touchscreen docking station for automatic bump testing, calibration, and datalogging (about 60 seconds per unit), and with the WatchGas SST-KIOSK compliance kiosk for fleet-level compliance check-in, alarm history upload, and user/location tracking.
If you're running a fleet of SST1 monitors across a refinery, mill, or smelter, the SST-DOCK + SST-KIOSK combination covers your bump/cal workflow and your compliance-tracking workflow together.
How does PK Safety support the SST1-S after purchase?
PK Safety carries the full WatchGas SST line and services the SST1-S with factory-trained technicians in-house. That includes SO2 sensor replacement when the cell reaches end-of-life, calibration, firmware updates, and warranty support (3-year instrument warranty, 2-year sensor warranty). Call 800.829.9580 to talk through your sulfur dioxide monitoring setup with someone who knows the SST1 platform — not a call-center script.
Not sure this is the right fit? Call PK Safety at 800.829.9580. A person who knows sulfur dioxide monitoring and the WatchGas SST platform will pick up.
You'll smell sulfur dioxide before you can see it — but by the time you're smelling it, you may already be at OSHA's permissible exposure limit.
SO2 has a pungent, unmistakable odor that most workers can detect between 0.5 and 3 ppm. That's the problem: OSHA's permissible exposure limit is 5 ppm as an 8-hour time-weighted average, and NIOSH's more conservative recommended limit is 2 ppm TWA with a 5 ppm short-term exposure limit. The concentration where you can smell SO2 and the concentration where you're already over the exposure limit overlap. Smell isn't a reliable measure of what you're breathing.
The WatchGas SST1-S Serviceable SO2 Gas Detector gives you a number instead of a nose.
It reads sulfur dioxide continuously in ppm across a 0–100 ppm range — spanning OSHA's PEL of 5 ppm through the NIOSH IDLH threshold of 100 ppm. Default alarm setpoints ship at Low 2 ppm (matching the NIOSH REL TWA) and High 5 ppm (matching OSHA's PEL and the NIOSH REL STEL). Configurable low, high, TWA, and STEL alarms let you tune the monitor to whichever standard your facility runs against — OSHA, NIOSH, ACGIH, or a stricter internal program.
Why refinery operators, mill supervisors, and smelter safety managers pick the SST1 line:
- Continuous SO2 monitoring in ppm with configurable Low, High, TWA, and STEL alarms — ship defaults already aligned to NIOSH REL
- Serviceable sensor — replace the SO2 sensor cell instead of the whole unit at end-of-life
- 3-year instrument warranty (vs. the industry-typical 2 years) with a 2-year sensor warranty
- 3-year replaceable battery based on typical alarm exposure
- Solid polymer sensor technology — compact, robust, temperature-tolerant
- NFC configuration and WatchGas App integration for datalogging
- Vibration + audible + visual alarms — you notice it on the operating floor or the boiler deck
- Bump test and calibration compatible with the WatchGas SST-DOCK; compliance check-in compatible with the WatchGas SST-KIOSK
Sensor and alarm specifications:
| Sensor | Gas measuring range | Low alarm (default) | High alarm (default) |
| SO2 | 0 – 100 ppm | 2 ppm | 5 ppm |
PK Safety services the full WatchGas SST line with factory-trained technicians in-house. We also handle BW/Honeywell (Factory Authorized Service Center), RKI, and RAE Systems monitors — one shop for a mixed-brand fleet. When the SO2 sensor drifts or needs replacement, send the unit to us — you're not shipping equipment into a black box. Call us at 800.829.9580 to talk through your sulfur dioxide monitoring setup with someone who understands SO2 detection and the WatchGas SST platform.
This is right for you if:
- You work in petroleum refining — sour crude handling, hydrotreating, sulfur recovery units
- You operate in pulp and paper — Kraft process, black liquor recovery, on-site sulfur recovery
- You supervise a steel plant, metal smelting operation (copper, zinc, lead), or sulfuric acid facility
- You run boilers, coal-fired power generation, or industrial combustion equipment where SO2 is present in flue gas
- You work in mining or mineral processing with sulfide ore roasting or smelting
- You need continuous SO2 exposure logs for OSHA respiratory protection compliance, EPA emissions monitoring, or internal safety audits
Technical documents:
Brochure
Specification Sheet
Quick Start Guide
Part Number: WG01-SST1-S — SST1-S Serviceable SO2 (Sulfur Dioxide) Gas Detector, 0–100 ppm range, real-time display
Frequently Asked Questions
What is the OSHA exposure limit for sulfur dioxide?
OSHA's permissible exposure limit (PEL) for sulfur dioxide is 5 ppm as an 8-hour time-weighted average, under 29 CFR 1910.1000 Table Z-1. NIOSH's recommended exposure limit (REL) is more conservative at 2 ppm TWA plus a 5 ppm short-term exposure limit (STEL) over any 15-minute period. ACGIH sets an even stricter TLV-STEL of 0.25 ppm, which some industrial safety programs use as an internal target.
The SST1-S ships with default alarm setpoints of Low 2 ppm and High 5 ppm — already aligned to the NIOSH REL. Configurable low, high, TWA, and STEL alarms let you tune the monitor to your facility's exposure program (OSHA, NIOSH, ACGIH, or a stricter internal standard).
Which industries typically require sulfur dioxide monitoring?
SO2 monitoring is a compliance requirement or best practice across a range of settings: petroleum refining (sour crude processing, hydrotreating, sulfur recovery units), pulp and paper (Kraft process, black liquor recovery, on-site sulfur recovery), metal smelting operations (copper, zinc, lead sulfide ore processing), sulfuric acid manufacturing, coal-fired power generation, industrial boilers and combustion equipment, and mining and mineral processing.
Any workplace where SO2 is produced or handled also falls under OSHA's respiratory protection standard (29 CFR 1910.134). Facilities in populated areas may additionally have EPA ambient-air and emissions-monitoring obligations under the Clean Air Act.
Can I detect SO2 by smell instead of using a monitor?
Not reliably. Sulfur dioxide has a pungent, sharp odor most workers can detect between 0.5 and 3 ppm — but that range overlaps with OSHA's exposure limit of 5 ppm. Individual odor detection thresholds vary widely, and chronic exposure can dull the sensation. Some workers smell SO2 well below the exposure limit; others don't notice it until they're already above it.
A continuous readout in ppm from the SST1-S shows the actual concentration regardless of nose sensitivity — and produces the audit-ready exposure log that compliance programs and internal safety reviews need.
What does "serviceable" mean on the SST1-S?
Traditional single-gas monitors are single-use — when the sensor reaches end-of-life (typically 2–3 years), the whole unit gets replaced. The SST1 platform is designed to be serviced: the SO2 sensor cell can be replaced, extending the monitor's service life beyond the sensor's own lifespan. Instrument warranty is 3 years; sensor warranty is 2 years. PK Safety services the WatchGas SST line in-house — send the unit in when the sensor needs replacement.
Does the SST1-S work with the WatchGas SST-DOCK and SST-KIOSK?
Yes to both. The SST1-S is fully compatible with the WatchGas SST-DOCK Touchscreen docking station for automatic bump testing, calibration, and datalogging (about 60 seconds per unit), and with the WatchGas SST-KIOSK compliance kiosk for fleet-level compliance check-in, alarm history upload, and user/location tracking.
If you're running a fleet of SST1 monitors across a refinery, mill, or smelter, the SST-DOCK + SST-KIOSK combination covers your bump/cal workflow and your compliance-tracking workflow together.
How does PK Safety support the SST1-S after purchase?
PK Safety carries the full WatchGas SST line and services the SST1-S with factory-trained technicians in-house. That includes SO2 sensor replacement when the cell reaches end-of-life, calibration, firmware updates, and warranty support (3-year instrument warranty, 2-year sensor warranty). Call 800.829.9580 to talk through your sulfur dioxide monitoring setup with someone who knows the SST1 platform — not a call-center script.
Not sure this is the right fit? Call PK Safety at 800.829.9580. A person who knows sulfur dioxide monitoring and the WatchGas SST platform will pick up.
Specifications
Specifications
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