GB/T 25848-2010 Industrial γ-ray level meter
1 Scope
This standard specifies types, requirements, inspection and test methods, inspection rules, marking, instructions for use, packaging, transportation and storage of the industrial γ-ray level meter (hereinafter referred to as the "level meter").
This standard is applicable to industrial γ-ray level meters.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB 3836.1 Explosive atmospheres - Part 1: Equipment - General requirements
GB 3836.2 Explosive atmospheres - Part 2: Equipment protection by flameproof enclosures "d"
GB 4075 Sealed radioactive sources - General requirements and classification
GB/T 4208-2017 Degrees of protection provided by enclosure (IP code)
GB 8702 Controlling limits for electromagnetic environment
GB/T 8993 Environmental conditions and testing procedures for nuclear instrumentation
GB/T 9969 General principles for preparation of instructions for use of industrial products
GB 11806 Regulations for the safe transport of radioactive material
GB/T 13384 General specifications for packing of mechanical and electrical product
GB 14052-1993 Radionuclide gauges - Gauges designed for permanent installation
3 Type
3.1 Structural type
Level meters fall into two structural types:
a) Split type: It consists of three parts: radioactive source, detector and converter;
b) Integrated type: It consists of two parts: radioactive source and detector.
Note: "Split type" refers to the split body of detector and converter, and the signal detected by the detector is sent to the converter for processing. "Integrated type" refers to that the converter is removed, and the converter and detector are integrated.
3.2 Product classification
Level meters are divided into switch type and continuous type.
3.3 Parameters
3.3.1 Measuring range: 100 mm to 8000 mm.
3.3.2 Output signal:
a) The output signal of switch is dry contact signal, and the contact capacity shall not be less than 20 W;
b) The continuous output signal is DC 4 mA ~ DC 20 mA current signal;
c) The integrated level meter carries out remote communication and debugging.
Note: DC refers to direct current (the same below).
3.4 Operating conditions
The normal operating conditions of the level meter are:
a) Ambient temperature:
Split type: the detector is -20°C ~ 50°C; the converter is 0°C ~ 50°C;
Integrated type: the detector is -20°C ~ 50°C;
b) Relative humidity: less than 90%.
c) Supply voltage: AC (220±22) V or DC (24±2.4) V.
d) There is no strong electromagnetic field interference and no strong vibration in the surrounding environment.
Note: AC refers to alternating current, and DC refers to direct current (the same below).
4 Requirements
4.1 Appearance
4.1.1 The enclosure of the level meter shall be smooth and intact, and the surface coating shall be painted and electroplated. There shall be no obvious scratches, bottom exposure, blistering, peeling, dirt and other phenomena.
4.1.2 The nameplate and mark of the level meter shall be clear.
4.1.3 Fasteners of the level meter shall not be loose, and various regulating devices shall rotate flexibly and function normally.
4.2 Requirements for explosion-proof performance
The explosion-proof performance of the level meter detector shall meet the requirements of GB 3836.1 and GB 3836.2, with an explosion proof certificate obtained.
4.3 Insulation resistance and strength
Foreword i
1 Scope
2 Normative references
3 Type
4 Requirements
5 Inspection and test methods
6 Inspection rules
7 Marking, instructions for use, packaging, transportation and storage
