WatchGas Replacement H2S Sensor SST-H-RPL
Description
When your H2S sensor drifts, you don't replace the whole monitor. You swap the sensor cell.
That's the operational advantage of the serviceable WatchGas SST1 line. Traditional single-gas monitors are single-use — when the sensor reaches end-of-life or a bump test reveals unrecoverable drift, the whole unit gets discarded. The SST1 platform is designed to be maintained: this WatchGas Replacement H2S Sensor drops into the
WatchGas SST1-H Serviceable H2S Gas Detector and any WatchGas SST4-series multi-gas monitor with an H2S sensor slot, extending the monitor's service life beyond the original sensor's lifespan.
What this sensor is (and isn't):
-
It IS a factory replacement H2S electrochemical sensor cell for the serviceable SST1-H monitor and any SST4-series multi-gas monitor (SST4-MINI, SST4-MICRO, SST4-PUMP) that includes H2S in its sensor set.
-
It is NOT compatible with the Limited-Life
SST1-H-24 (2-year) or
SST1-H-36 (3-year) alert-only monitors — those are non-serviceable by design and are discarded at end-of-life. If you're using the alert-only variants, you replace the whole monitor, not the sensor.
-
It is NOT a standalone gas detection device. The sensor cell requires a compatible WatchGas SST monitor to function.
Solid polymer electrochemical sensor technology. The dry-cell design eliminates the liquid electrolyte used in traditional electrochemical sensors, giving the cell better long-term stability, no leak risk in truck-bed or field storage, and better tolerance for temperature extremes. It also produces ultra-low power consumption compared to older H2S sensor designs — one of the reasons the SST1-H can run for its full battery life without a mid-cycle charge.
When to replace an H2S sensor cell:
- The sensor fails a bump test and won't recover on recalibration
- Calibration drift exceeds acceptable tolerance across successive cal events
- The monitor displays a sensor fault code specific to the H2S channel
- The sensor's warranty period (2 years) has elapsed and calibration reliability starts trending down
- You're rotating a fleet's sensor generation on a proactive maintenance cadence (industry best practice for high-stakes confined-space programs)
Who buys the SST-H-RPL:
- Owners of the WatchGas SST1-H serviceable H2S monitor whose current sensor has drifted, failed a bump, or reached end-of-warranty
- Owners of the WatchGas SST4-MINI, SST4-MICRO, or SST4-PUMP multi-gas monitors whose H2S channel needs replacement
- Confined-space program managers doing scheduled sensor rotations to stay ahead of drift and out of compliance risk
- Safety supervisors at facilities where H2S is a chronic hazard (petroleum, wastewater, pulp and paper, agricultural sludge handling) and monitor uptime matters
- Fleet managers running proactive maintenance cycles rather than reactive replacements
Sensor specifications:
Gas
Sensor technology
Warranty
Compatible monitors
H2S (hydrogen sulfide)
Solid polymer electrochemical (dry-cell)
2 years
SST1-H, SST4-MINI, SST4-MICRO, SST4-PUMP
Key features:
- High accuracy across the full detection range
- Long operational lifetime — 2-year warranty
- Ultra-low power consumption (optimized for battery-operated and IoT-integrated monitors)
- High precision at low H2S concentrations — critical for NIOSH REL-aligned monitoring
- No zero drift
- Silicone-resistant (no poisoning by common industrial silicone contaminants)
- Direct linearity across the detection range
- High temperature range tolerance
PK Safety services the full WatchGas SST line with factory-trained technicians in-house. If you'd rather send the monitor to us for sensor replacement than swap the cell yourself, we handle that in-house — full swap, calibration verification against a certified H2S standard, and return-to-service. We also service BW/Honeywell (Factory Authorized Service Center), RKI, and RAE Systems monitors — one shop for a mixed-brand fleet's sensor lifecycle. Call us at
800.829.9580 to talk through your H2S sensor replacement workflow with someone who understands the SST1 / SST4 platform.
Technical documents (WatchGas SST1):
SST1 Brochure
Part Number: WG01-SST-H-RPL — WatchGas Replacement H2S Sensor
Frequently Asked Questions
Which WatchGas monitors is the SST-H-RPL sensor compatible with?
The SST-H-RPL is compatible with any WatchGas SST-platform monitor that includes an H2S sensor slot:
-
SST1-H Serviceable H2S Gas Detector — the single-gas H2S monitor is designed around this sensor
-
SST4-MINI Diffusion 4-Gas Detector — H2S is one of the four sensors in the standard configuration
-
SST4-MICRO Diffusion 4-Gas Detector — same H2S sensor slot
-
SST4-PUMP 4-Gas Detector — same H2S sensor slot
The SST-H-RPL is NOT compatible with the Limited-Life
SST1-H-24 (2-year) or
SST1-H-36 (3-year) alert-only monitors — those are non-serviceable by design. When their sensors reach end-of-life, you replace the whole monitor, not the sensor cell.
How do I know it's time to replace my H2S sensor?
Four common signals:
-
The sensor fails a bump test and won't recover after recalibration. Bump testing before each use is the industry-standard way to verify sensor response; a persistent bump failure means the sensor cell is no longer detecting reliably.
-
Calibration drift exceeds acceptable tolerance across successive cal events. If each calibration is nudging the sensor's baseline further from the reference, the cell is degrading.
-
The monitor displays a sensor fault code specific to the H2S channel. Cell exhaustion, extreme temperature or humidity exposure, or physical damage can trigger a fault.
-
The sensor is out of its warranty period. The SST-H-RPL carries a 2-year warranty. Beyond that, sensor reliability trends down and proactive replacement is best practice for confined-space entry programs where sensor accuracy is the difference between compliance and a missed alarm.
Can I install the SST-H-RPL myself, or do I need to send the monitor to PK Safety?
Both paths work. The SST1 platform is designed for user sensor replacement — the sensor cell is accessed through the monitor's service compartment, and the WatchGas SST1 manual walks through the swap procedure. After installation, you'll need to complete a full calibration to verify the new sensor's response against a known H2S standard.
If you'd rather not run the swap yourself — for example, if you don't have a calibration workflow set up, or if you want a factory-trained technician to verify the sensor's performance across its full range before it goes back into service — send the monitor to PK Safety. We handle the swap, full calibration verification, and return-to-service in-house.
Should I replace the sensor or buy a new SST1-H monitor?
The SST-H-RPL sensor cell costs $160. A full new
SST1-H monitor costs $290. If your monitor's housing, display, battery, and electronics are in good working order and only the H2S sensor has drifted or reached end-of-life, the sensor replacement is the more cost-effective path — roughly 55% of the full-monitor price for the maintenance action that gets your fleet back to compliance.
If the monitor itself has physical damage, a battery that no longer holds charge, or a display that's failing, a full monitor replacement is the better path. PK Safety can help you evaluate — call 800.829.9580 with your monitor's condition and we'll walk you through the choice.
How is the SST-H-RPL calibrated after installation?
After installing the new sensor cell in the monitor, run a full calibration cycle using an H2S calibration gas standard. For multi-gas monitors, use the
PK Safety WatchGas Equivalent 4-Gas Calibration Gas Mix (contains LEL, O2, CO, H2S at cal-standard concentrations). For a dedicated single-gas cal, use a standalone H2S cylinder (typically 25 ppm H2S in air balance).
Automated calibration is fastest using the
WatchGas SST-DOCK Touchscreen docking station — one docking cycle handles bump test and full calibration in about 60 seconds. Manual calibration through the monitor's menu also works if the SST-DOCK isn't part of your workflow.
How does PK Safety support the SST-H-RPL after purchase?
PK Safety carries the full WatchGas SST platform, including replacement sensors for every gas in the SST1 and SST4 sensor sets. We service SST1 and SST4 monitors in-house with factory-trained technicians — if your sensor swap results in a persistent calibration issue or the new sensor doesn't seat correctly, send us the monitor and we'll troubleshoot.
Call
800.829.9580 to talk through your sensor replacement workflow, or to arrange in-house sensor swap and calibration verification.
Not sure whether a sensor swap or full monitor replacement is the right path? Call PK Safety at 800.829.9580. A person who knows the SST platform's service ecosystem will pick up.
Read more
Description
When your H2S sensor drifts, you don't replace the whole monitor. You swap the sensor cell.
That's the operational advantage of the serviceable WatchGas SST1 line. Traditional single-gas monitors are single-use — when the sensor reaches end-of-life or a bump test reveals unrecoverable drift, the whole unit gets discarded. The SST1 platform is designed to be maintained: this WatchGas Replacement H2S Sensor drops into the WatchGas SST1-H Serviceable H2S Gas Detector and any WatchGas SST4-series multi-gas monitor with an H2S sensor slot, extending the monitor's service life beyond the original sensor's lifespan.
What this sensor is (and isn't):
- It IS a factory replacement H2S electrochemical sensor cell for the serviceable SST1-H monitor and any SST4-series multi-gas monitor (SST4-MINI, SST4-MICRO, SST4-PUMP) that includes H2S in its sensor set.
- It is NOT compatible with the Limited-Life SST1-H-24 (2-year) or SST1-H-36 (3-year) alert-only monitors — those are non-serviceable by design and are discarded at end-of-life. If you're using the alert-only variants, you replace the whole monitor, not the sensor.
- It is NOT a standalone gas detection device. The sensor cell requires a compatible WatchGas SST monitor to function.
Solid polymer electrochemical sensor technology. The dry-cell design eliminates the liquid electrolyte used in traditional electrochemical sensors, giving the cell better long-term stability, no leak risk in truck-bed or field storage, and better tolerance for temperature extremes. It also produces ultra-low power consumption compared to older H2S sensor designs — one of the reasons the SST1-H can run for its full battery life without a mid-cycle charge.
When to replace an H2S sensor cell:
- The sensor fails a bump test and won't recover on recalibration
- Calibration drift exceeds acceptable tolerance across successive cal events
- The monitor displays a sensor fault code specific to the H2S channel
- The sensor's warranty period (2 years) has elapsed and calibration reliability starts trending down
- You're rotating a fleet's sensor generation on a proactive maintenance cadence (industry best practice for high-stakes confined-space programs)
Who buys the SST-H-RPL:
- Owners of the WatchGas SST1-H serviceable H2S monitor whose current sensor has drifted, failed a bump, or reached end-of-warranty
- Owners of the WatchGas SST4-MINI, SST4-MICRO, or SST4-PUMP multi-gas monitors whose H2S channel needs replacement
- Confined-space program managers doing scheduled sensor rotations to stay ahead of drift and out of compliance risk
- Safety supervisors at facilities where H2S is a chronic hazard (petroleum, wastewater, pulp and paper, agricultural sludge handling) and monitor uptime matters
- Fleet managers running proactive maintenance cycles rather than reactive replacements
Sensor specifications:
| Gas | Sensor technology | Warranty | Compatible monitors |
| H2S (hydrogen sulfide) | Solid polymer electrochemical (dry-cell) | 2 years | SST1-H, SST4-MINI, SST4-MICRO, SST4-PUMP |
Key features:
- High accuracy across the full detection range
- Long operational lifetime — 2-year warranty
- Ultra-low power consumption (optimized for battery-operated and IoT-integrated monitors)
- High precision at low H2S concentrations — critical for NIOSH REL-aligned monitoring
- No zero drift
- Silicone-resistant (no poisoning by common industrial silicone contaminants)
- Direct linearity across the detection range
- High temperature range tolerance
PK Safety services the full WatchGas SST line with factory-trained technicians in-house. If you'd rather send the monitor to us for sensor replacement than swap the cell yourself, we handle that in-house — full swap, calibration verification against a certified H2S standard, and return-to-service. We also service BW/Honeywell (Factory Authorized Service Center), RKI, and RAE Systems monitors — one shop for a mixed-brand fleet's sensor lifecycle. Call us at 800.829.9580 to talk through your H2S sensor replacement workflow with someone who understands the SST1 / SST4 platform.
Technical documents (WatchGas SST1):
SST1 Brochure
Part Number: WG01-SST-H-RPL — WatchGas Replacement H2S Sensor
Frequently Asked Questions
Which WatchGas monitors is the SST-H-RPL sensor compatible with?
The SST-H-RPL is compatible with any WatchGas SST-platform monitor that includes an H2S sensor slot:
- SST1-H Serviceable H2S Gas Detector — the single-gas H2S monitor is designed around this sensor
- SST4-MINI Diffusion 4-Gas Detector — H2S is one of the four sensors in the standard configuration
- SST4-MICRO Diffusion 4-Gas Detector — same H2S sensor slot
- SST4-PUMP 4-Gas Detector — same H2S sensor slot
The SST-H-RPL is NOT compatible with the Limited-Life SST1-H-24 (2-year) or SST1-H-36 (3-year) alert-only monitors — those are non-serviceable by design. When their sensors reach end-of-life, you replace the whole monitor, not the sensor cell.
How do I know it's time to replace my H2S sensor?
Four common signals:
- The sensor fails a bump test and won't recover after recalibration. Bump testing before each use is the industry-standard way to verify sensor response; a persistent bump failure means the sensor cell is no longer detecting reliably.
- Calibration drift exceeds acceptable tolerance across successive cal events. If each calibration is nudging the sensor's baseline further from the reference, the cell is degrading.
- The monitor displays a sensor fault code specific to the H2S channel. Cell exhaustion, extreme temperature or humidity exposure, or physical damage can trigger a fault.
- The sensor is out of its warranty period. The SST-H-RPL carries a 2-year warranty. Beyond that, sensor reliability trends down and proactive replacement is best practice for confined-space entry programs where sensor accuracy is the difference between compliance and a missed alarm.
Can I install the SST-H-RPL myself, or do I need to send the monitor to PK Safety?
Both paths work. The SST1 platform is designed for user sensor replacement — the sensor cell is accessed through the monitor's service compartment, and the WatchGas SST1 manual walks through the swap procedure. After installation, you'll need to complete a full calibration to verify the new sensor's response against a known H2S standard.
If you'd rather not run the swap yourself — for example, if you don't have a calibration workflow set up, or if you want a factory-trained technician to verify the sensor's performance across its full range before it goes back into service — send the monitor to PK Safety. We handle the swap, full calibration verification, and return-to-service in-house.
Should I replace the sensor or buy a new SST1-H monitor?
The SST-H-RPL sensor cell costs $160. A full new SST1-H monitor costs $290. If your monitor's housing, display, battery, and electronics are in good working order and only the H2S sensor has drifted or reached end-of-life, the sensor replacement is the more cost-effective path — roughly 55% of the full-monitor price for the maintenance action that gets your fleet back to compliance.
If the monitor itself has physical damage, a battery that no longer holds charge, or a display that's failing, a full monitor replacement is the better path. PK Safety can help you evaluate — call 800.829.9580 with your monitor's condition and we'll walk you through the choice.
How is the SST-H-RPL calibrated after installation?
After installing the new sensor cell in the monitor, run a full calibration cycle using an H2S calibration gas standard. For multi-gas monitors, use the PK Safety WatchGas Equivalent 4-Gas Calibration Gas Mix (contains LEL, O2, CO, H2S at cal-standard concentrations). For a dedicated single-gas cal, use a standalone H2S cylinder (typically 25 ppm H2S in air balance).
Automated calibration is fastest using the WatchGas SST-DOCK Touchscreen docking station — one docking cycle handles bump test and full calibration in about 60 seconds. Manual calibration through the monitor's menu also works if the SST-DOCK isn't part of your workflow.
How does PK Safety support the SST-H-RPL after purchase?
PK Safety carries the full WatchGas SST platform, including replacement sensors for every gas in the SST1 and SST4 sensor sets. We service SST1 and SST4 monitors in-house with factory-trained technicians — if your sensor swap results in a persistent calibration issue or the new sensor doesn't seat correctly, send us the monitor and we'll troubleshoot.
Call 800.829.9580 to talk through your sensor replacement workflow, or to arrange in-house sensor swap and calibration verification.
Not sure whether a sensor swap or full monitor replacement is the right path? Call PK Safety at 800.829.9580. A person who knows the SST platform's service ecosystem will pick up.
When your H2S sensor drifts, you don't replace the whole monitor. You swap the sensor cell.
That's the operational advantage of the serviceable WatchGas SST1 line. Traditional single-gas monitors are single-use — when the sensor reaches end-of-life or a bump test reveals unrecoverable drift, the whole unit gets discarded. The SST1 platform is designed to be maintained: this WatchGas Replacement H2S Sensor drops into the WatchGas SST1-H Serviceable H2S Gas Detector and any WatchGas SST4-series multi-gas monitor with an H2S sensor slot, extending the monitor's service life beyond the original sensor's lifespan.
What this sensor is (and isn't):
- It IS a factory replacement H2S electrochemical sensor cell for the serviceable SST1-H monitor and any SST4-series multi-gas monitor (SST4-MINI, SST4-MICRO, SST4-PUMP) that includes H2S in its sensor set.
- It is NOT compatible with the Limited-Life SST1-H-24 (2-year) or SST1-H-36 (3-year) alert-only monitors — those are non-serviceable by design and are discarded at end-of-life. If you're using the alert-only variants, you replace the whole monitor, not the sensor.
- It is NOT a standalone gas detection device. The sensor cell requires a compatible WatchGas SST monitor to function.
Solid polymer electrochemical sensor technology. The dry-cell design eliminates the liquid electrolyte used in traditional electrochemical sensors, giving the cell better long-term stability, no leak risk in truck-bed or field storage, and better tolerance for temperature extremes. It also produces ultra-low power consumption compared to older H2S sensor designs — one of the reasons the SST1-H can run for its full battery life without a mid-cycle charge.
When to replace an H2S sensor cell:
- The sensor fails a bump test and won't recover on recalibration
- Calibration drift exceeds acceptable tolerance across successive cal events
- The monitor displays a sensor fault code specific to the H2S channel
- The sensor's warranty period (2 years) has elapsed and calibration reliability starts trending down
- You're rotating a fleet's sensor generation on a proactive maintenance cadence (industry best practice for high-stakes confined-space programs)
Who buys the SST-H-RPL:
- Owners of the WatchGas SST1-H serviceable H2S monitor whose current sensor has drifted, failed a bump, or reached end-of-warranty
- Owners of the WatchGas SST4-MINI, SST4-MICRO, or SST4-PUMP multi-gas monitors whose H2S channel needs replacement
- Confined-space program managers doing scheduled sensor rotations to stay ahead of drift and out of compliance risk
- Safety supervisors at facilities where H2S is a chronic hazard (petroleum, wastewater, pulp and paper, agricultural sludge handling) and monitor uptime matters
- Fleet managers running proactive maintenance cycles rather than reactive replacements
Sensor specifications:
| Gas | Sensor technology | Warranty | Compatible monitors |
| H2S (hydrogen sulfide) | Solid polymer electrochemical (dry-cell) | 2 years | SST1-H, SST4-MINI, SST4-MICRO, SST4-PUMP |
Key features:
- High accuracy across the full detection range
- Long operational lifetime — 2-year warranty
- Ultra-low power consumption (optimized for battery-operated and IoT-integrated monitors)
- High precision at low H2S concentrations — critical for NIOSH REL-aligned monitoring
- No zero drift
- Silicone-resistant (no poisoning by common industrial silicone contaminants)
- Direct linearity across the detection range
- High temperature range tolerance
PK Safety services the full WatchGas SST line with factory-trained technicians in-house. If you'd rather send the monitor to us for sensor replacement than swap the cell yourself, we handle that in-house — full swap, calibration verification against a certified H2S standard, and return-to-service. We also service BW/Honeywell (Factory Authorized Service Center), RKI, and RAE Systems monitors — one shop for a mixed-brand fleet's sensor lifecycle. Call us at 800.829.9580 to talk through your H2S sensor replacement workflow with someone who understands the SST1 / SST4 platform.
Technical documents (WatchGas SST1):
SST1 Brochure
Part Number: WG01-SST-H-RPL — WatchGas Replacement H2S Sensor
Frequently Asked Questions
Which WatchGas monitors is the SST-H-RPL sensor compatible with?
The SST-H-RPL is compatible with any WatchGas SST-platform monitor that includes an H2S sensor slot:
- SST1-H Serviceable H2S Gas Detector — the single-gas H2S monitor is designed around this sensor
- SST4-MINI Diffusion 4-Gas Detector — H2S is one of the four sensors in the standard configuration
- SST4-MICRO Diffusion 4-Gas Detector — same H2S sensor slot
- SST4-PUMP 4-Gas Detector — same H2S sensor slot
The SST-H-RPL is NOT compatible with the Limited-Life SST1-H-24 (2-year) or SST1-H-36 (3-year) alert-only monitors — those are non-serviceable by design. When their sensors reach end-of-life, you replace the whole monitor, not the sensor cell.
How do I know it's time to replace my H2S sensor?
Four common signals:
- The sensor fails a bump test and won't recover after recalibration. Bump testing before each use is the industry-standard way to verify sensor response; a persistent bump failure means the sensor cell is no longer detecting reliably.
- Calibration drift exceeds acceptable tolerance across successive cal events. If each calibration is nudging the sensor's baseline further from the reference, the cell is degrading.
- The monitor displays a sensor fault code specific to the H2S channel. Cell exhaustion, extreme temperature or humidity exposure, or physical damage can trigger a fault.
- The sensor is out of its warranty period. The SST-H-RPL carries a 2-year warranty. Beyond that, sensor reliability trends down and proactive replacement is best practice for confined-space entry programs where sensor accuracy is the difference between compliance and a missed alarm.
Can I install the SST-H-RPL myself, or do I need to send the monitor to PK Safety?
Both paths work. The SST1 platform is designed for user sensor replacement — the sensor cell is accessed through the monitor's service compartment, and the WatchGas SST1 manual walks through the swap procedure. After installation, you'll need to complete a full calibration to verify the new sensor's response against a known H2S standard.
If you'd rather not run the swap yourself — for example, if you don't have a calibration workflow set up, or if you want a factory-trained technician to verify the sensor's performance across its full range before it goes back into service — send the monitor to PK Safety. We handle the swap, full calibration verification, and return-to-service in-house.
Should I replace the sensor or buy a new SST1-H monitor?
The SST-H-RPL sensor cell costs $160. A full new SST1-H monitor costs $290. If your monitor's housing, display, battery, and electronics are in good working order and only the H2S sensor has drifted or reached end-of-life, the sensor replacement is the more cost-effective path — roughly 55% of the full-monitor price for the maintenance action that gets your fleet back to compliance.
If the monitor itself has physical damage, a battery that no longer holds charge, or a display that's failing, a full monitor replacement is the better path. PK Safety can help you evaluate — call 800.829.9580 with your monitor's condition and we'll walk you through the choice.
How is the SST-H-RPL calibrated after installation?
After installing the new sensor cell in the monitor, run a full calibration cycle using an H2S calibration gas standard. For multi-gas monitors, use the PK Safety WatchGas Equivalent 4-Gas Calibration Gas Mix (contains LEL, O2, CO, H2S at cal-standard concentrations). For a dedicated single-gas cal, use a standalone H2S cylinder (typically 25 ppm H2S in air balance).
Automated calibration is fastest using the WatchGas SST-DOCK Touchscreen docking station — one docking cycle handles bump test and full calibration in about 60 seconds. Manual calibration through the monitor's menu also works if the SST-DOCK isn't part of your workflow.
How does PK Safety support the SST-H-RPL after purchase?
PK Safety carries the full WatchGas SST platform, including replacement sensors for every gas in the SST1 and SST4 sensor sets. We service SST1 and SST4 monitors in-house with factory-trained technicians — if your sensor swap results in a persistent calibration issue or the new sensor doesn't seat correctly, send us the monitor and we'll troubleshoot.
Call 800.829.9580 to talk through your sensor replacement workflow, or to arrange in-house sensor swap and calibration verification.
Not sure whether a sensor swap or full monitor replacement is the right path? Call PK Safety at 800.829.9580. A person who knows the SST platform's service ecosystem will pick up.
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Specifications
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MPN
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Product Weight (lbs.)
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Country of Origin
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