The Honeywell HST-PP4 is an immersion-type liquid temperature sensor belonging to the HST-P series, widely used in HVAC water systems, central air conditioning chilled and hot water networks, and industrial circulating water systems.
Core Specifications
| Parameter | Technical Specification |
| Model | HST-PP4 |
| Brand / Series | Honeywell HST-P Series Pipe Water Temperature Sensor |
| Sensing Element / Output | Pt1000 Platinum RTD (Resistance signal output) |
| Probe Length (Insertion Depth) | 102 mm |
| Measuring Temperature Range | -40°C to +150°C (-40°F to 302°F) |
| Ambient Temperature Range | -40°C to +70°C (-40°F to 158°F) |
| Accuracy | High accuracy (typically $\pm 0.2\text{K}$) |
| Process Connection | Standard G 1/2″ thread |
| Probe Material | SS304 Stainless Steel (with standard stainless steel thermowell) |
| Enclosure Protection Class | IP65 (Dust-tight and water-resistant, with flame-retardant PC housing UL94-V0) |
Key Features & Applications
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Precise Measurement: Utilizes a high-stability Pt1000 platinum resistance element to accurately and linearly convert fluid temperatures inside pipelines into electrical signals for controllers.
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Easy Installation: Comes with a matching stainless steel thermowell and standard G 1/2″ threaded connection, supporting safe installation and removal in pressurized or circulating water pipes.
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Wide Application: Frequently used for temperature monitoring and automated control in commercial building (office buildings, hospitals, hotels, shopping malls) central air conditioning chilled water, cooling water, heat exchange stations, and district heating networks.









