

在线溶解臭氧传感器
Pi公司的OzoSense在线溶解臭氧分析仪由Pi公司设计,用于测量水中的臭氧浓度,安装和操作简单,具有无与伦比的稳定性、准确性和精密度,同时具有卓越的性价比。
OzoSense系列臭氧分析仪是当今世界上最先进和最好的臭氧传感器
OzoSense 系列传感器是一种对pH值变化不敏感的膜式传感器。不需使用任何试剂,非常稳定,并且大大减少了维护量,降低了整个使用周期的成本。
在线溶解臭氧传感器与控制器相连,组成世界级的在线臭氧浓度监测和控制方案。如需更多Pi公司的控制器的信息, 请点击。
工作原理
OzoSense系列膜法安培臭氧传感器是一个双电极传感器,工作时施加了高电势,从而消除零点漂移。其独特的设计意味着根本不需要试剂或缓冲剂。


- 稳定可靠-卓越的臭氧过程控制-在线溶解臭氧控制器
- 适用于所有饮用水、工艺水和盐溶液
- 最多6个月的维护周期
- 最多3个月一次校准
- 不受余氯干扰
- 不受水中清洁剂的干扰
- PID控制-在线溶解臭氧控制器
- 数据记录和图表功能
- 通信选项如TCP/IP, Modbus, Profibus等等。
OzoSense系列的臭氧传感器和流通池可与不同的溶解臭氧控制器配套,加上不同的通信,显示,和控制选项,为你提供伟大的性能。
OzoSense系列的臭氧传感器不受氯等氧化剂的干扰。加上其出色的零点稳定性和校准稳定性,它非常适合监测无论是清洁或恶劣的环境下的残留的溶解臭氧。
OzoSense系列的臭氧传感器无需缓冲剂和试剂,这意味着它具备较低的成本和较长的维护间隔(6个月)。它正迅速成为仪器工程师性价比最高的选择。


OzoSense在线溶解臭氧分析仪现正安装于多个应用系统,包括:
- 瓶装水厂-臭氧监测仪
- 臭氧投加控制-臭氧控制器
- 偏远站点
- 冷却塔
- 食物生产
- 医院
- 二级臭氧化
- 废水臭氧化
任何需要在线测量水中残余臭氧的地方,都可以使用OzoSense臭氧监测仪。OzoSense特别适合在可靠性和易用性要求高的场合使用。该传感器可以抵抗洗涤剂的干扰,适用于很多洗涤的应用。
溶解臭氧分析仪选项
多参数系统
OzoSense系列在线臭氧监测仪可与其他传感器配套组成多参数系统。这样的灵活性在提供臭氧控制解决方案的同时可以节省大量的金钱。
Document | Type | Size |
---|---|---|
OzoSense |
Brochure | 802kB |
CRONOS® |
Brochure | 712kB |
CRIUS® |
Brochure | 733kB |
CRIUS® Remote Communications |
Brochure | 669kB |
CRONOS® and CRIUS® Control Options |
Technical Note | 649kB |
Remote Access GPRS |
Technical Note | 593kB |
Autoflush |
Brochure | 411kB |
Probe Fouling |
Technical Note | 316kB |
我可以测量海水中的臭氧吗?
我多久校准一次溶解臭氧监测仪?
我多久更换一次电解液?
我可以在有洗涤剂的情况下测量臭氧吗?
我能在超压情况下使用臭氧传感器吗?这样我就能把样品送回生产过程中去。
pH值变化会影响读数吗?
膜片和电解液的保质期是多长时间?
干扰因子有哪些?
传感器是由什么材料做的?
传感器的适应温度范围是多少?
为什么臭氧传感器不需要零点调整?
温度变化会有什么影响?
用什么来校准传感器?
当我取样做DPD测试时,我需要考虑什么?
我试着校准,但分析仪说样品不稳定?
什么是臭氧?
为什么用臭氧消毒?
溶解的臭氧是一种强氧化剂,因此可以用来消毒水。特别是它可以:
- 与锰发生反应,除去锰
- 消灭一些对氯有抗性的病原体,如鞭毛虫和隐孢子虫。
为什么臭氧特别适用于某些应用?
臭氧监测仪、臭氧分析仪和臭氧控制器的区别是什么?
臭氧监测仪和臭氧分析仪没有区别。它们只是两个不同的人互换使用的表达方式。臭氧控制器是一个臭氧监测仪或分析仪,具有在线控制功能。所以对于Pi 的OzoSense来说,臭氧控制器、分析仪和监视器之间实际上没有区别。
如果您对溶解臭氧在线监测和控制有任何疑问,请随时联系我们。
Focus Ons are a series of short articles distributed by email providing technical information regarding instrumentation, process measurement in potable, waste, process and pool waters. If you would like to join the mailing list, please contact us.
Focus On… Calibrating Sensors Using a DPD Kit
You probably know that most chlorine, ozone and chlorine dioxide analysers are calibrated using hand held DPD kits but…
… did you know that DPD can’t tell you when you have no residual?
… did you know that errors on DPD performance can be up to ± 100%?
… did you know that a significant number of service calls received by Pi relate to poor calibration?
DPD (N.N-diethyl-p-phenylenediamine) is a chemical that when mixed with water containing an oxidant, changes colour depending on the concentration of the oxidant present. A handheld colourimeter measures light passing through the coloured solution. The absorption of that light by the liquid gives a concentration value. It is usually used to check concentration of, for example, free chlorine, total chlorine, ozone and chlorine dioxide etc. in water.


When the DPD kit gives a value, it is often used to calibrate online instruments……and that is where Pi comes in!
As a manufacturer of online instruments we have to understand DPD in order to help our customers when they have problems calibrating their online monitors.
This Focus On will look at:
- The limitations of DPD (turbidity, zero oxidant, bleaching, pH and interferents).
- Minimising DPD measurement error (sampling, alignment and cleaning).
- Things to look out for (low concentrations, pink colour, stained glass).
- Little known chemistry (measuring bromine, chlorite versus chlorine dioxide).
- Rinse and repeat: is it really worth repeating my measurement?
What are the limitations of DPD?
DPD cannot measure zero oxidant well.
DPD works using the absorption of light, and turbidity in the sample will give a positive reading. This means if there is no oxidant in the sample, any turbidity introduced to the sample after ‘zero’ such as undissolved tablet or powder will cause the DPD test kit to give a small reading, this is why…
DPD cannot measure below approximately 0.05 ppm.


If you suspect there is zero oxidant in your sample, hold the vial up to a white surface. If you cannot see any trace of pink colour, it is likely any reading you are getting is from the unreacted DPD tablet.
DPD cannot measure free chlorine above 6 ppm
(and won’t always give a ‘high concentration’ reading error).
Many people are unaware that past a certain level of oxidant, DPD will not form its characteristic pink colour, and instead will ‘bleach’ to form a clear solution. This can lead people to think there is little or no oxidant in their water, when in fact there is so much that it is bleaching their DPD. Be on the lookout for a flash of pink when the tablet or powder is added if you suspect your sample is being bleached. NB. special kits and reagents are available for measuring oxidant above 6 ppm.
DPD cannot measure in extremes of alkalinity or pH.
DPD tablets, powdered pillows, and drops contain buffers that will change the pH of your solution in order to facilitate DPD reacting with your oxidant. There is only so much buffering capability in the powder or tablet, and if your sample has an extreme of pH or alkalinity this could affect the concentration reading from the DPD handset.
DPD cannot distinguish between oxidants such as:
chlorine, chlorine dioxide, chlorite, ozone, organochlorides, bromine and more, meaning interferents are a big problem.
DPD is a fantastic chemical, in that it is very versatile as a colouring agent, which is how it gives the oxidant the colour that we measure. This versatility does come at a price, DPD is not very specific as an analysis tool, and so if other chemicals are present in the sample, they can interfere with the reading, giving an inaccurate result. Common interferents include chlorine dioxide (for chlorine measurement, and vice versa), sodium chlorite, ozone, organochloramines, peroxides, and many more.
DPD cannot distinguish between colour and turbidity.
Any undissolved solids, including unreacted DPD tablet, will affect the reading. Sample turbidity should be accounted for in the zero measurement. If the zero measurement has a high turbidity, this will affect the sensitivity of the colourimeter, due to the large correction it must perform to account for absorption by undissolved solids. Allowing any solids in the sample several seconds to settle after mixing is the best way to counteract this.
Minimising DPD measurement error
Here is an easy to read, printable checklist to ensure accurate DPD readings every time.
Things to look out for
When was the last time your DPD was calibrated?
Like all measurement devices, handheld DPD colourimeters can drift over time, and need to be calibrated. Check your device manual for how often it should be calibrated, if you can’t remember the last time it was calibrated, chances are it needs doing again!
Stained Glass


The pink solution formed after DPD tests can leave a residue behind on the glass, which will affect the DPD reading. This residue can be easily cleaned off using what is in your DPD kit.
Tap water
If you use normal tap water to wash out vials, droplets left behind can affect your reading due to the residual chlorine in drinking water. It is best (but not always practical) to use deionised water to wash out your vials, but if this isn’t available (deonised water can be purchased as car battery top up water from any car parts supplier) then you can use cooled boiled tap water, as boiling gets rid of any chlorine. If not then simply make sure the vials are perfectly dry before use.
Little Known Chemistry
DPD has a wide range of interferents. This means recurrent problems can sometimes be caused by the chemical makeup of the sample. For example, chlorite (ClO2–) and chlorine dioxide both affect DPD, but only chlorine dioxide is measured by most chlorine dioxide amperometric sensors.
DPD can be used to track bromine, but DPD No.1 tablets measure FREE chlorine or TOTAL bromine. As combined bromine is just as effective a disinfectant as free bromine, this generally doesn’t pose too much of a problem, however some amperometric sensors measure free bromine, and cannot be calibrated using DPD No.1 tablets. For more information on measuring bromine, or chlorine in seawater, please see Pi’s technical note on Seawater Chlorination.
Rinse and repeat
How important is it to repeat my DPD measurement? Isn’t it a waste of time?
A sensor is only as good as its last calibration, and the sensor will be as accurate as you calibrate it to be. If you need your sensor for tight process control, such as a pool or dosing controller, then it is essential to repeat the DPD test at least twice, if not more. The reason it’s important to repeat the test is mainly due to human error, but variation in DPD tablets has been known, or it could be a slight concentration spike that you happened to pick up in your sample. With each repetition these circumstances become less and less likely, giving you more confidence in the value you use to calibrate your analyser.
Pi recommends the following routine for calibration:
Perform a DPD test, and compare the reading to your analyser.
- Is the reading within 10% of your analyser? If yes, leave the analyser alone.
- If the reading is not within 10%, repeat the DPD test.
- Is the second test within 10% of the first test? If yes, calibrate your instrument to this reading. If not, keep repeating the DPD tests until 2 consecutive tests are within 10%, then calibrate the machine to this reading.
Focus On… Probe Fouling
Many different sites ranging across the whole water industry have a daily struggle to keep instrumentation functioning correctly due to fouling. However did you know that…
… self cleaning and self flushing systems are now available from Process Instruments for most types of sensors?
… these fouling removal systems can extend the life of sensors and drastically reduce maintenance regimes?
… Pi’s self cleaning/flushing systems are affordable, simple and trouble free by design?
What is the problem?
Sensor Fouling


Whatever the process being monitored is, there is often something in the sample water capable of fouling a sensor, and therefore causing erroneous results. The obvious solution to this problem is to clean the sensor, but how regular should inspection and cleaning programs be for each piece of instrumentation? Too regular and the inspection and cleaning regime is time consuming and unnecessarily costly. Not often enough and the instrumentation will give false results and probably fail prematurely.
What is the solution?
Process Instruments’ Autoclean and Autoflush Systems
Simple, reliable and easy to maintain, Process Instruments’ Autoclean/Autoflush systems are an alternative to mechanical cleaning mechanisms which can clog and break. By regularly spraying the sensor/probe with clean water or air, the sensor remains clean and free from fouling for extended periods of time. The sensor cleaning cycle is activated by Pi’s controller for a user selectable length of time and frequency so that no matter how dirty the application, the probe remains clean. With no moving parts in the sensor body or in the cleaning attachment there is nothing to replace or check other than a simple valve positioned in an easy to reach location.
Pi’s Autoclean and Autoflush systems can give trouble free and fouling free functioning of sensors for weeks, if not months, at a time.
A solution for each application
Autoclean


This option can be added to our pH, ORP, Turbidity, Suspended Solids and Dissolved Oxygen (DO) sensors. Consisting of an end cap to direct the flow of clean water (or air for a DO sensor) across the face of the sensor blasting any dirt away. The cleaning is controlled by a single valve positioned in an easily accessible location.
Autoverify
If using air to clean a DO sensor the system can also automatically verify that the sensor is still responding correctly, removing any need to remove the sensor from the sample for months at a time.
Autoflush


For sensors that require flow cell mounting like Chlorine, Ozone and Chlorine Dioxide, an Autoflush system has inbuilt valves which automatically start/stop the sample flow and control the flow of clean water past the probe. The user can set the flushing interval and duration to keep the flow cell and sensor clear from fouling. For particularly dirty or stubborn contaminants, warm water can be used as the flush water to aid cleaning.
With the above options, whatever the application or parameter being measured, Process Instruments will be able to provide a monitoring system that will not only be accurate, precise and long lasting but that will also remain free from fouling and save the operator both time and money.