Product Overview
The OHTS1099 is a universal precipitation measurement sensor based on the strain gauge weighing principle, designed for comprehensive meteorological and hydrological monitoring applications. Capable of monitoring solid, liquid, and mixed-phase precipitation, this device employs a high-precision load cell to deliver accurate measurements across a wide dynamic range. With a real-time precipitation intensity measurement range of 6 ~ 1800 mm/h and resolution of 0.1 mm, the sensor provides reliable data for weather stations, hydrological monitoring, and environmental research.
The product features an intelligent automatic temperature-controlled heating module that activates when ambient temperature falls below 1°C and deactivates when exceeding 9°C, effectively preventing the catchment orifice from freezing during winter conditions. Additionally, the automatic drainage function triggers when water volume reaches 80% of the measurement range, enabling continuous unattended operation. The enclosure adopts a convex windproof structural design that reduces evaporation loss and improves catch efficiency, while dual output interfaces via RS485 (Modbus-RTU protocol) and pulse signals ensure seamless integration with existing monitoring networks. Compliant with SL21-2015 specifications and suitable for low-power solar applications, the OHTS1099 is ideal for remote and harsh environment deployments.
Features
Universal Precipitation Monitoring: Based on strain gauge weighing technology, the sensor accurately measures solid, liquid, and mixed-phase precipitation including rain, snow, and sleet, making it suitable for all-season meteorological observation.
Wide Dynamic Range: Supports precipitation intensity measurements from 6 ~ 1800 mm/h with 0.1 mm resolution, capturing everything from light precipitation to heavy rainfall events with high fidelity.
High Precision Measurement: Delivers exceptional accuracy with ± 0.2 mm error for precipitation ≤ 10 mm and ± 2% for precipitation > 10 mm, meeting stringent meteorological monitoring standards.
Automatic Temperature Control: Features an intelligent heating system that automatically activates below 1°C and deactivates above 9°C, preventing freezing and snow blockage while optimizing power consumption.
Intelligent Drainage System: Automatic drainage mechanism activates at 80% capacity threshold, ensuring continuous operation without manual intervention during extended precipitation events.
Windproof Design: The convex enclosure structure minimizes wind interference and reduces evaporation losses, improving measurement accuracy in exposed installations.
Dual Output Interfaces: Supports both RS485 digital communication with Modbus-RTU protocol and pulse output signals, providing flexibility for integration with various data loggers and monitoring systems.
Low Power Operation: Designed for energy efficiency with 0.15 W quiescent power consumption, supporting off-grid solar power supply for remote monitoring stations.
Applications
The OHTS1099 weighing rain gauge is suitable for diverse environmental monitoring applications including precipitation observation at hydrological monitoring stations and rainfall data acquisition at meteorological stations. It serves critical roles in marine environment precipitation monitoring and disaster early warning systems for emergency management departments.
Additional applications include road waterlogging monitoring for transportation systems, water volume assessment for agricultural and forestry irrigation management, and micro-meteorological monitoring for power systems. The device also supports precipitation research for national defense and scientific studies, providing reliable data across industrial, agricultural, and research sectors.
Technical Specifications
| Parameter | Specification |
|---|---|
| Supply Voltage | 12 V DC |
| Quiescent Power | 0.15 W (DC 12 V) |
| Heating Power | 30 W (Optional, DC 12 V) |
| Measurement Range | 0 ~ 1000 mm |
| Resolution | 0.1 mm |
| Catchment Diameter | φ 200 mm (0 ~ +0.6 mm tolerance) |
| Measurement Error | ± 0.2 mm (when ≤ 10 mm); ± 2% (when > 10 mm) |
| Operating Temperature | -35°C ~ +65°C |
| Operating Humidity | 0% RH ~ 95% RH (Non-condensing) |
| Precipitation Intensity Range | 6 ~ 1800 mm/h |
| Output Interface | RS485 (Modbus-RTU), Pulse |
| Pulse Equivalent | 0.1 mm/pulse |
| Heating Start Temperature | < 1°C |
| Heating Stop Temperature | > 9°C |
| Auto-Drain Threshold | 80% of range |
| Communication Baud Rate | 1200/2400/4800/9600/19200/38400/57600/115200 bit/s, default 4800 bit/s |
Physical Specifications
| Parameter | Specification |
|---|---|
| Foundation Dimensions | 150 cm × 150 cm × 50 cm (L×W×D) |
| Foundation Mounting Holes | φ 18 mm, depth 12 ~ 15 cm |
| Wind Shield Height Adjustment | Fixing ring upper surface 2 cm above the upper edge of the catchment orifice |
FAQ
Q: What is the measurement principle of the OHTS1099 rain gauge?
A: The OHTS1099 employs a strain gauge weighing principle using a high-precision load cell to measure precipitation. It can detect solid, liquid, and mixed-phase precipitation with a resolution of 0.1 mm and measurement range of 0 ~ 1000 mm.
Q: How does the automatic heating system work?
A: The device features an automatic temperature-controlled heating module that activates when ambient temperature falls below 1°C and deactivates when exceeding 9°C. This prevents the catchment orifice from freezing during cold weather operations. The heating power is 30 W at DC 12V.
Q: What is the auto-drainage mechanism?
A: The rain gauge includes an intelligent automatic drainage function that triggers when the water volume reaches 80% of the measurement range. This allows for continuous monitoring without requiring manual emptying of the collection bucket.
Q: What precautions are needed for operation below 0°C?
A: When operating below 0°C, antifreeze (ethylene glycol or methanol mixture) must be added to the collection bucket to prevent freezing. The antifreeze mixing ratio depends on the historical average minimum temperature, ranging from 0 liters at 0°C to 6.5 liters ethylene glycol and 9.5 liters methanol at -35°C. If antifreeze is not used, ensure precipitation does not exceed 80% of bucket volume to avoid irreversible damage.
Q: What maintenance does the OHTS1099 require?
A: The inner wall of the catchment orifice should be wiped regularly with a soft cloth to maintain cleanliness. Remove leaves and foreign objects promptly to ensure unobstructed water flow. Monthly cleaning is recommended under long-term operating conditions, with cleaning required at least every three months. When antifreeze or evaporation suppressant oil is low, add appropriate amounts. Lightning protection safety inspections should be conducted annually in spring.