Automatic water quality proportional samplerIt is a device specifically designed for collecting water quality samples, which can achieve multiple sampling methods (such as quantitative sampling, timed quantitative sampling, timed flow proportional sampling, fixed flow quantitative sampling, and remote control sampling) and multiple bottling methods (such as single sampling per bottle - single sampling and multiple sampling per bottle - mixed sampling) according to the requirements of water sample sampling. It is an ideal sampling tool for scientific monitoring of rivers, lakes, and water discharged by enterprises.
The working principle of the water quality proportional automatic sampler is to extract the water sample from the flowing water body into the system through a sampling pump, and implement a series of operations in the system to make the sampling process fast, accurate, and reliable. Specifically, the sampling system includes components such as a programmable logic controller (PLC), metering pump, sampling bottle, etc. PLC can automatically identify and adjust the working status and flow rate of the sampling pump according to the preset sampling scheme, thereby achieving the effect of proportional sampling. The metering pump is responsible for accurately measuring the sampling volume and emptying the residual liquid after each sampling to prepare for the next sampling.
Automatic water quality proportional samplerComposed of multiple precision components and systems working together, the main components are as follows:
1. Sampling unit (core execution component)
Sampling pump:
Type: Peristaltic pumps are commonly used, and some also use self-priming pumps or vacuum pumps.
Function: By squeezing the hose to generate negative pressure, the water sample is sucked into the equipment from the sampling point.
Advantages: The fluid only contacts the hose and does not come into contact with the pump body, avoiding cross contamination and easy maintenance.
Sampling pipeline:
Composed of corrosion-resistant and non-toxic hoses (such as silicone tubing and fluoroplastic tubing), connecting the sampling probe, pump, and distribution unit.
Responsible for transporting water samples from the water source to the sampling bottle.
Inlet probe/filter:
Installed at sampling points (such as rivers and pipelines), it usually comes with a filter or sedimentation cup to prevent large particles of impurities, mud, water plants, etc. from entering the pipeline and causing blockage.
2. Sample storage unit
Sampling bottle rack:
Used to fix multiple (usually 6, 12, 24 or more) sampling bottles and divide them into bottles for sampling in order or at designated positions.
Sampling bottle:
Generally, wide mouthed bottles made of polyethylene (PE) or polypropylene (PP) materials have a capacity of 500ml or 1000ml.
Pre cleaning is required, and if necessary, fixing agents (such as acid, alkali, etc., according to the requirements of the monitoring project) should be added.
Refrigeration system (optional but common):
Built in compressor or semiconductor (electronic) refrigeration device.
Store the sampling bottle in a low-temperature environment of 4 ± 2 ° C to inhibit microbial activity, prevent water sample deterioration, and ensure sample stability.
3. Control and Data Processing Unit
Central controller (main control board):
The 'brain' of a device is usually based on a microcontroller or embedded system.
Responsible for receiving instructions, controlling the operation of various components, and storing data.
Human computer interaction interface:
LCD display screen (LCD) and buttons are used to set sampling mode, time, frequency, bottle number and other parameters, view operating status and historical records.
The high-end model is equipped with a touch screen.
Real time clock (RTC):
The clock chip with built-in battery power ensures that time is not lost after power failure and guarantees the accuracy of timed sampling.
4. Sampling mode and signal input unit
Time Proportional Sampling:
Automatically collect water samples at preset intervals (such as every 1 hour, every 2 hours).
Flow Proportional Sampling:
External flow meters (such as electromagnetic flow meters, ultrasonic flow meters) are required.
The controller receives flow signals and triggers sampling proportionally based on cumulative or instantaneous flow (such as sampling once every 100 tons of water flowing through).
Signal interface: Supports 4-20mA, RS485, pulse and other signal inputs.
External trigger sampling:
Sampling can be triggered by switch signals (such as rain gauges and alarm signals) for emergency monitoring.
5. Allocation and pipeline cleaning unit
Sample distribution device:
In the multi bottle sampling mode, control the water sample to flow into the designated sampling bottle. It can be achieved by rotating the valve or moving the pump head.
Automatic cleaning system:
Built in cleaning water tank or connected to cleaning water source.
Automatically rinse the pipeline with deionized water or purified water before and after sampling to prevent residue and cross contamination.
Some equipment has a blowback function, which uses gas to remove accumulated water in the pipeline.
6. Power supply and safety protection unit
Power module:
Supports AC 220V mains power supply.
Built in rechargeable batteries (such as lead-acid and lithium batteries) ensure that the scheduled sampling tasks or data can be completed or saved even after a power outage.
safeguard:
Bottle shortage alarm: Check if the sampling bottle is properly placed.
Pipeline blockage alarm: detect abnormal pump pressure or flow.
Liquid level alarm: detect the water level in the cleaning water tank or waste liquid tank.
Power outage memory: After a power outage, restore power and automatically resume unfinished sampling procedures.
Door magnetic switch: An alarm is triggered when the box door is opened to prevent human interference.
7. Data output and communication unit
Data storage:
Built in memory, records sampling time, bottle number, flow data, alarm information, etc.
Communication interface:
RS232/RS485: Used to connect to an upper computer or data acquisition system.
USB interface: Export data or connect to a USB drive.
Ethernet/GPRS/4G (high-end models): enables remote monitoring, parameter setting, and data transmission, supporting Internet of Things (IoT) applications.