Nitrate nitrogen online analyzer, online nitrate nitrogen analyzer

The nitrate nitrogen online analyzer is a new generation fully automatic nitrate nitrogen online analyzer based on the Chinese standard method of oxidation-reduction photometry. The nitrate nitrogen in the water sample is changed in color by adding a color developer, and the degree of color change in the solution corresponds to the concentration of nitrate nitrogen in the water sample. The instrument can directly determine the nitrate nitrogen value of the water sample through photoelectric colorimetry.

Main points

The analyzer has a simple structure, wide measurement range, fast measurement speed, low operating cost, and no secondary pollution. It can directly measure tap water, Rivers and Lakes water, industrial sewage and wastewater with concentration before water treatment. It can be widely used in water environment automatic monitoring stations, sewage treatment plants, water treatment plants, sewage monitoring points, regional water boundary points, water quality analysis rooms, and various environmental regulatory agencies for monitoring water environment.

2.2 Main points

The water sample treatment device is maintenance free, ensuring that the maintenance cycle of the pre-treatment device is over six months.

The chemical digestion time can be adjusted, and the measurement process and results can meet both domestic standards and environmental industry standards.

The full port device and innovative analysis flow path and reagent formula ensure measurement reproducibility, which can currently reach 5%.

Fully automatic operation, no need for personnel on duty, can achieve automatic zeroing, automatic calibration, automatic measurement, automatic cleaning, automatic maintenance, self-protection, automatic recovery and other functions.

The online measurement methods are diverse, allowing for manual measurement at any time, automatic timed measurement, automatic periodic measurement, and other measurement methods. Optical quantitative devices enable simultaneous sampling of immiscible solutions.

L supports power-off storage function, and data will not be lost in case of power failure.

Instrument installation

Unpacking and inspection

Before installing the analyzer, it is necessary to check the packaging box and analyzer for any damage, inspect the connections of all hardware and cables of the instrument, as well as the connections of the entire analysis system pipeline, and eliminate any looseness caused during transportation; At the same time, check whether there are any damaged or cracked glassware such as quantitative tubes and reactors during transportation. Be very careful when performing these checks.

Position requirements

This analyzer is designed for indoor operation and should be installed indoors. The whole set of instruments includes an analyzer and pre-processing. The analyzer is installed on top of the pre-processing, and the whole set of instruments is vertically placed in a suitable position. The ideal installation location should be dry, ventilated, and easy to control temperature. For ease of operation, the analyzer should be installed parallel or slightly away from the eyes.

The measurement of the analyzer can be optimized according to the following standards:

Choose a location as close as possible to the sampling point to install the analyzer. It is recommended that the distance between the sampling point and the analyzer should not exceed 10 meters to accommodate the delay in monitoring result output.

The placement of the instrument should ensure that the water sample tube is connected to the pre-treatment box from the left side of the instrument as much as possible.

The installation location temperature is within the range of (5-40) ℃.

There is a heating device in a room with a low temperature.

There is air conditioning in rooms with high temperatures, but the installation position of the instrument cannot face directly towards the air conditioning vent.

Install in a dry location and avoid direct sunlight.

The installation location should be free of irritating or corrosive gases.

There is no obvious mechanical vibration around the installation point.

There is no strong electromagnetic interference such as large motors around the installation point.

Mechanical Installation

Choose a site with a flat ground and good ventilation as the installation location for the equipment, place the pre-treatment chassis, and ensure that the chassis is at least 50 centimeters away from the wall to facilitate the smooth progress of installation and debugging work. After selecting the installation location, place the pre-processing chassis to ensure that it can be placed horizontally. If the ground level does not meet the requirements, add some cork and fine tune the pre-processing chassis legs to ensure that the chassis is level. If the vibration intensity at the installation site of the instrument is too high, a cushioning block should be placed to ensure that the instrument is not affected by vibration interference.

The placement of the analyzer in the monitoring room

After placing the preprocessing device, place the TN host box next to the preprocessing device.

pipeline connection

After installing the chassis, it is necessary to investigate the spatial conditions between the sampling point and the instrument placement point, while considering the local climate conditions.

If there are no obstacles (such as walls, roads, etc.) between the sampling point and the instrument installation point, and the local temperature does not freeze throughout the year, then a short distance of a PVC pipe with a diameter of 25 is directly laid from the sampling point to the lower left of the online analyzer as the water pipe of the analyzer. The outlet pipe of the instrument can be determined according to the actual situation of the user. The drainage ditch that is convenient for the analyzer can be used as the outlet pipe of the analyzer according to the principle of proximity. At this time, a short distance of a PVC pipe with a diameter of 25 is also laid from the drainage ditch to the lower left of the online analyzer as the outlet pipe of the analyzer. If there is an actual situation of freezing in winter in the local area, the sampling pipes laid on the ground are required to use heating pipes for heat tracing treatment. At the same time, the sampling pipes, cable pipes, and heating pipes should be wrapped with a layer of insulation cotton for insulation, in order to prevent the water samples in the sampling pipes from freezing and blocking the pipes during the monitoring process in winter.

If there is a situation where the pipeline cannot be directly laid between the sampling point and the instrument installation point (such as walls, roads, etc.), the pipeline should be laid underground. The depth of the pipeline laying underground can be determined according to the actual situation of the user. Considering that the buried pipeline and the power control of the sewage pump (such as submersible pump) need to bear a certain heavy pressure, it is recommended to install a slightly larger diameter pressure steel pipe outside the pipeline during the laying of the underground pipeline to ensure that the water pipe and wires are not damaged by external pressure.

If the local climate conditions still allow for freezing in winter, based on the actual situation in most areas where the soil freezing line is less than 2 meters, the sampling tube, power cord, and outer pressure tube can be buried in the soil layer below 2 meters, and insulation cotton can be lined between the pressure tube and the sampling tube for insulation. The pipeline laying also ensures that the drop between the sampling point of the water sample and the water sampling port of the monitoring instrument is not less than 0.5 meters, in order to ensure that the water sample can flow back to the source water after detection, and to reduce the possibility of freezing and blocking the pipeline inside the sampling pipeline.

After the pipeline laying route is completed, the connection of the pipeline can be carried out at the same time. The distance between the monitoring point and the online analyzer can be measured, and then the required length of the water pipe and the number of bends between the monitoring point and the instrument can be calculated based on the allowed route of the pipeline. At least one ball valve needs to be installed at the pre-treatment outlet of the instrument. If the pressure of the water sample taken by the sewage pump is too high, at least one ball valve and three tees should be installed at the pre-treatment outlet of the instrument to form a pressure divider circuit.

The connection between the water sample pipe and the sewage pump can be determined based on the type of sewage pump. The sewage pump can be determined according to the water depth of the sampling point, the drop between the sampling point and the ground, and the convenience of the user. Submersible pumps cannot be used for sampling points with a water depth of less than 50cm, and self-priming pumps cannot be used for sampling points with a drop of more than 3 meters from the ground. Other situations can be determined through consultation with the user. Tap water can be connected according to the water sample situation.

electrical connection

The monitoring room should be able to provide a power supply capacity of AC220V, 50Hz, and a power capacity of not less than 5kVA. In addition, the voltage stability of the power supply should not exceed 10% of the rated voltage. When the voltage stability does not meet this requirement, it is strongly recommended that users configure a regulated power supply. The online analyzer and other electrical systems in the monitoring room should adopt a single grounding method, and the grounding resistance should not exceed 1 Ω.

On the left side of the monitor host box, there are three black connectors from top to bottom. The top one has a 4-20mA data transmission line interface, the second one is the monitor power line interface, and the third one is the sewage pump control line interface. The host power supply uses 220VAC/50Hz AC power supply, and the sewage pump control line is used to directly connect with the power line of the external sampling sewage pump. This control line can output 220VAC/50Hz AC to drive the sampling sewage pump, so the sampling sewage pump does not need to be powered separately.

communication connection

Communication connection is a type of connection operation used when users need to send real-time monitoring results from online analyzers to their superiors. The specific connection method should be determined according to the user's on-site requirements. The user should have a device with data transmission function, such as a data acquisition instrument. Then, according to the user's data transmission requirements, if the user uses 4-20mA to transmit data, the data transmission line of the online analyzer is a two core cable, which can be connected to the corresponding data transmission interface of the data acquisition instrument; If the user requests to use RS232 serial port for data transmission, the data transmission line of the online analyzer is a cable with DB9 terminal, which can be connected to the corresponding data transmission interface of the data acquisition instrument.