Overview
The YD-890 is a continuous on-line γ radiation monitor designed specifically for decay tank wastewater applications. Built on a 32-bit high-speed embedded microprocessor with a 1024 × 600 colour touchscreen LCD, the system delivers real-time dose rate monitoring and alarm functionality in a clear, intuitive interface. Each detector probe features an IP68-rated waterproof enclosure, purpose-built for long-term immersion in demanding wastewater environments.
The main unit communicates with each probe via reliable RS485 (Modbus protocol), displaying real-time dose rate data and continuous probe status — online, offline, or alarm — for every connected detector. For broader facility integration, detectors may be interfaced directly with a PLC, and the relevant communication protocol is supplied to engineering contractors for seamless incorporation into decay tank discharge control systems, helping to streamline project implementation.
The YD-890 is designed for γ activity concentration trend monitoring. The software platform generates a visual exponential decay curve, providing clear operational oversight. Note: This instrument is intended for trend monitoring and alarm purposes only; its readings shall not be used as the sole basis for clearance or release decisions, which must be made in accordance with applicable local regulations and certified laboratory analysis.
Key Features
Safety Interlock Against Accidental Release
A waterproof GM probe acts as a secondary safety interlock. Should high-activity liquid — such as excreta from patients following ¹³¹I administration — be inadvertently introduced into the decay tank ahead of scheduled discharge, the interlock prevents accidental release, even where local regulations would otherwise permit time-based discharge.
Visualised Decay Curve for Regulatory Verification
24/7 on-line monitoring generates a complete exponential decay curve on the software platform. This visual record is suitable for submission to relevant nuclear safety authorities (e.g., AELB, CNEN) as evidence of regulatory compliance and sound management practice.
Maintenance-Free Industrial-Grade UPVC / CPVC Enclosure
The detector housing is constructed of industrial-grade waterproof PVC (or CPVC), offering significantly lower radioactive iodine adsorption compared with stainless steel. Resistant to chemical corrosion from pharmaceutical waste and designed for prolonged immersion, the material minimises background buildup and eliminates the need for frequent decontamination.
Applications
- Liquid waste from radioisotope production
- Radiological laboratory wastewater
- Decay tanks in nuclear medicine departments
Technical Specifications
| Parameter | Specification |
|---|---|
| Detector | GM counter tube (or scintillator) |
| Measurement range | 0.01 μSv/h – 3500 μSv/h (150 mSv/h) |
| Display units | CPM, μSv/h |
| Sensitivity | >5 CPS at 1 μSv/h |
| Response time | ≤2 s |
| Relative intrinsic error | ≤±15% |
| Energy response | 48 keV – 3 MeV, ≤±30% |
| Communication protocol | Modbus / RS485 |
| Power supply | 220 V AC mains |
| Operating environment | Temperature -10°C to +50°C; acid-resistant, corrosion-resistant |
| Probe waterproof rating | IP68 |
| Dimensions | Main unit: 260 × 160 × 68 mm (excluding base); Detector probe: φ162 × 57 mm |