The turbidity value is the quantitative statement of the qualitative phenomenon of turbidity. The objective of measuring turbidity is to obtain information on the concentration of scattering particles in a medium (solids concentration). This can be done by either of two fundamentally different methods: determination of the light loss of the transmitted beam (scatter coefficient) or determination of the intensity of the light scattered sideways. The scatter coefficient represents the total scattered light that has been withdrawn from the incident beam, while the scatter intensity states how much scattered light has been deflected at a given angle.
Fig. 53: Determination of the light loss of the transmitted beam
Fig. 54: Measurement of the light scattered sideways
Both variables are proportional to the particle concentration and are therefore suitable for measuring turbidity. But they differ in their applicability at various concentration levels. Measurement of the scatter intensity permits the detection of lower concentrations, while transmission measurement is used for higher concentrations. The reason for this is the phenomenon of multiple scatter. At low concentrations, the light scattered by a given particle has room to propagate freely (simple scatter). At higher concentrations, however, two things happen: the particles closer to the light source tend to screen off the incident light, and the scattered light can no longer propagate freely. As a result, the scatter intensity no longer increases in proportion to the concentration.
Simple scatter is limited to about 10 FNU. In practice, however, electronic linearization makes it possible to use scatter intensity measurement for much higher measuring ranges (up to 4000 FNU). The lowest measurable turbidity level depends on how much stray light is present.
Measurement of the light loss of the transmitted beam permits the detection of high concentrations, but is limited at the lower levels. The trouble is that a large number of particles are necessary to detect the reduction of transmitted light reliably. In practice, transmission measurement covers a span from 50 FNU to 20,000 FNU.
Practical interpretation of the turbidity value is achieved by comparison with a standard suspension, i.e. turbidimeters are calibrated with a reference solution (usually formazine). An instrument that has been calibrated with formazine will measure any formazine concentration correctly. When it comes to other turbid media, one cannot be certain of a direct correlation between turbidity value and solids concentration, because the reading will be affected also by the particle size and the refractive index of the particles in relation to the medium.
Attempts to compare the readings produced by different instruments are admissible only if they have the same characteristics with regard to wavelength of the light, scatter angle, optical configuration, calibration and colour compensation. For that reason, standards have been defined for many applications, e.g. for drinking water the standard ISO 7027. For continuous measurements in industrial processes, the measuring technique applied (photometer) is also extremely important because of the need for high stability.
Ostern: 07.–10. April 2023, Auffahrt: 18. Mai 2023, Pfingstmontag: 29. Mai 2023, Fronleichnam: 08. Juni 2023, Bundesfeiertag: 01. August 2023, Maria Himmelfahrt: 15. August 2023, Allerheiligen: 01. November 2023, Maria Empfängnis: 08. Dezember 2023, Betriebsferien: 23. Dezember 2023 – 02. Januar 2024
Monday–Friday 08:00am–12:00pm und 1:30pm–5:00pm
Public & company holidays:
Easter: 07.–10. April 2023, Ascension Day: 18. May 2023, Whit Monday: 29. May 2023, Corpus Christi: 08. June 2023, Federal Holiday: 01. August 2023, Assumption Day: 15. August 2023, All Saints Day: 01. November 2023, Conception of Mary: 08. December 2023, Company holidays: 23. December 2023 – 02. January 2024
Install the apllication contained in the zip file.
Provide your logon credentials (email and password) from sigrist.com.
Set an empty directory as target.
Start the synchronisation.
How do I sync documents to my Android device?
FolderSync Lite synchronizes our Document Cloud to your Android device. Use your favorite file manager to explore files and open them.
How do I sync the documents to my OS X device?
GoodSync For Mac (30$) synchronizes our Document Cloud to your Mac.
Or connect to our WebDAV server (https://documents.sigrist.com/), and use an app like Sync Folders to synchronize with your local drive.
How can I select what documents are beeing synchronized to my device?
2.3. It is our particular concern that we protect and safely store all your personal data entrusted to us. This document provides more information on how we use and process personal data.
3. Purpose, legal basis, storage period and data recipient
3.1. The personal data collected by Sigrist-Photometer AG are needed for the purposes of customer service and promotion. In addition, we analyse the usage patterns of visitors browsing the website for the purpose of personalisation and demand specific preparation of information. The data are collected, stored, processed and used for these purposes.
3.2. Sigrist-Photometer AG collects, processes and uses your personal data on the legal basis of Art. 6 (1) GDPR. The legal basis for the processing of your personal data are, on the one hand, legitimate interests in accordance with Art 6 (1) (f) GDPR and, on the other hand, your consent to the processing of your relevant personal data in accordance with Art. 6 (1) (a) (newsletter, contact form and cookies). Not providing the data may have various consequences.
3.3. Sigrist-Photometer AG processes your personal data, as far as necessary, for the duration of the entire business relationship (from initiation, handling until expiration of a contract) and, exceeding that, in accordance with the legal safekeeping and documentation obligations accruing from Swiss laws and until a possible legal dispute is ended, continual warranty and guarantee periods expire.
3.4. In the course of operating our website and analysing the usage patterns or visitors browsing our website, we assign processors, i.e. software and hosting service suppliers as well as agencies, which may access your personal data in the course of their work as far as these data are necessary for rendering their respective services. They have committed themselves to us to comply with the data protection provisions. Processing contracts in accordance with Art. 28 GDPR have been concluded. More detailed information concerning the processors can be requested at [email protected].
4. Contact form (pending)
4.1. Your information and personal data given in our contact form is transmitted to us, processed and stored by us via our own mail server for the purpose of processing your enquiry. These data are not collected or passed on without your consent. However, without these data, your enquiry cannot be processed.
4.2. Data processing is carried out in accordance with the legal requirements of Art. 6 (1) (a) (Consent) GDPR.
5.1. You can register for our newsletter on our website following a double opt-in process. After your registration, you will receive an e-mail requesting your confirmation of registration. Without your e-mail address, our newsletter cannot be transmitted. You can unsubscribe our newsletter at any time by activating the unsubscribe-link at the end of each newsletter.
5.2. For forwarding our newsletters, we assign a processor (newsletter service provider), who in turn committed themselves to us to comply with the relevant data protection provisions. A processor contract in accordance with Art. 28 GDPR has been concluded. More detailed information concerning the processors can be requested at [email protected].
5.3. Data processing is carried out in accordance with the legal requirements of Art. 6 (1) (a) (Consent) GDPR. You can find detailed information on our newsletter privacy statement here.
6. Google Analytics and cookies
6.1. This website uses Google Analytics, a web analysis supplier of Google Inc. (»Google«), 1600 Amphitheatre Parkway Mountain View, CA 94043, USA. Google Analytics uses »cookies« which are text files that are saved on your computer to help t analyse how you use the website. The information generated by the cookie about your use of this website (including your IP-address) will be transmitted to and stored by Google on servers in the USA. The IP-address transmitted by your browser within Google Analytics will not be merged with other Google data. Google will use this information on behalf of the website operator for the purpose of evaluating your use of the website, compiling reports on website activities for website operators and providing other services relating to website activity and internet usage. If necessary, Google will transmit this information to third parties provided this is prescribed by law or if third parties process there data on behalf of Google. Our legitimate interest in the processing of data lies in these purposes. The use of Google Analytics is governed by § 15 (3) TMA or Art. 6 (1) (f) GDPR.
6.2. By using our website, you consent to our using cookies. You may refuse the acceptance of cookies by selecting the appropriate settings on your browser software. As to the details, please refer to the instructions provided by the supplier of your browser. The full functionality of this website may be restricted if you decide against certain technical and/or functional cookies. Some cookies remain stored on your terminal device until you delete them.
6.3. We have concluded a corresponding contract for data processing with the web analysis provider (»Google«), who committed themselves to us to comply with the valid data protection regulations. Detailed information on the processor can be requested at [email protected].
6.4. Your IP address will be recorded but immediately pseudonymized. By using the code extension, the last 8 bits of the IP addresses will be deleted and thus anonymized. Accordingly, only a rough localization is now possible.
6.5. Data processing is carried out in accordance with the legal requirements of Art. 6 GDPR (in particular consent). You can find detailed data protection information on Google Analytics here.
7. Consent and withdrawal of consent
7.1. If your consent is necessary for processing your data, we will only process said data after your express consent.
7.2. We do not process data of minors and we are not entitled to do so. By giving your consent, you also acknowledge that you have reached the age of 14 or that your legal representatives have given their consent.
7.3. You can withdraw your consent at any time at the following e-mail address: [email protected].
In such a case, all your data stored will be anonymised and further used for statistical purposes only without personal references. Withdrawal of consent does not affect the legality of data processing carried out as a result of the consent until said consent was withdrawn.
8. Data security
8.1. Sigrist-Photometer AG will take technical and organisational safety measures for safeguarding stored personal data against accidental or deliberate manipulation, loss or destruction and against the access of unauthorised persons. Our safety measures are continually improved in accordance with technical progress.
9. Your rights
9.1. 9.1. You have the right to be informed about your stored personal data at any time. Provided there is no legal retention period, you have the right to have your data deleted as well as to oppose its being processed. Moreover, you have the right to have your data corrected as well as to have its processing restricted, to the transferability of said data as well as to complain before the Swiss data protection authority (https://www.edoeb.admin.ch/edoeb/en/home.html).
9.2. As regards your rights, please contact us at [email protected] or write to us at:
Privacy statement Google Analytics
This website uses Google Analytics, a web analysis service of Google Inc. (»Google«), 1600 Amphitheatre Parkway Mountain View, CA 94043, USA. This use is governed by Art. 6 (1) (f) GDPR.
Google Analytics uses »cookies« which are text files that are saved on your computer to help the website analyse how users use the site. The information generated by the cookie about your use of this website will be transmitted to and stored by Google on servers in the USA.
Sigrist-Photometer AG activated the IP-anonymization of this website. Accordingly, Google will shorten your IP-address within the member states of the European Union or in other contracting states of the European Economic Area beforehand. Only in exceptional cases will the complete IP address be transmitted to the Google server in the USA and shortened there. The IP address transmitted by your browser within Google Analytics will not be merged with other Google data.
Google will use this information on behalf of the website operator for the purpose of evaluating your use of the website, compiling reports on website activities for website operators and providing other services relating to website activity and internet usage. Our legitimate interest in the processing of data lies in these purposes. The use of Google Analytics is governed by § 15 (3) TMG or Art. 6 (1) (f) GDPR.
The data transmitted by us and linked with cookies, user identification (e.g. user ID) or advertising ID are automatically deleted after 14 months. The deletion of data reaching the end of their storage period is carried out automatically once month. You can find further information on conditions of use and privacy on https://www.google.com/analytics/terms/gb.html or on https://policies.google.com/?hl=en.
You may refuse the storage of cookies by selecting the appropriate settings on your browser software; however, please note that if you do this you may not be able to use the full functionality of this website. You can prevent the collection of the data generated by the cookie and relating to your use of the website (including your IP address) and the processing of these data by Google by downloading and installing the browser add-on available under the following link: https://tools.google.com/dlpage/gaoptout?hl=en-GB
As an alternative to the browser add-on, especially for browsers on mobile devices, you can further prevent the collection by Google Analytics: an opt-out cookie is set preventing the futures collection of your data when visiting this website. This opt-out cookie works only in this browser and only for our website and is stored on your device. If you delete the cookies in this browser, you will have to re-set the opt-out cookies. Information on embedding the opt-out cookie can be found on:
https://developers.google.com/analytics/devguides/collection/gajs/?hl=de#disable in the paragraph »Disabling Tracking«.
If necessary, Sigrist-Photometer AG will implement other Google services to individualize advertisements (Google DoubleClick, Google Dynamic Re-Marketing, Google Tag Manager) or to compile conversion statistics (Google AdWords Conversion). If you do not want this, you can deactivate it with the following link: https://adssettings.google.com/authenticated
Sigrist-Photometer AG, Hofurlistrasse 1, 6373 Ennetbürgen, Switzerland (hereafter referred to as »Sigrist« or »we«) offer visitors browsing the Sigrist-Photometer AG website (www.sigrist.com, hereinafter referred to as »website«) a free subscription of the Sigrist newsletter (hereinafter referred to as »newsletter«).
In the following we provide information on the processing of personal data within the newsletter subscription in accordance with Art. 13 and Art. 14 of the General Data Protection Regulation (»GDPR«).
Data collected during the subscription process for the newsletter
Step 1: E-mail address (obligatory)
Step 2: Title, first name, last name, company, country and language of correspondence (optional)
Step 3: Industry (optional)
During a newsletter registration on the Sigrist website, we also collect the country specific version as language of correspondence.
Log data collected during the registration and deregistration for the newsletter for technical reasons
(»registration and deregistration data«)
Date and time of confirmation of application (registration and confirmation) in double-opt-in process as well as the IP address of the terminal device used for confirmation, date and time of a possible deregistration of the newsletter
Log data collected during opening our newsletter and newsletter articles via the hypertext transfer protocol (http) for technical reasons
IP address, type and version of your internet browser and mail program, type of the terminal device used, date and time of access
Data stored in cookies in the browser of our newsletter subscriber when opening our newsletter
(»newsletter cookie data«)
Unambiguous ID for (re-)identification of the newsletter subscriber
Data in user profiles, that we generate by analysing the user behaviour in the newsletter
(»newsletter user profile data«)
Data on the usage of the newsletter, in particular opening, opening rate and clicking behaviour (number of clicks, clicking rate) in the newsletters opened and their articles, links and attachments
Independently generated by the e-mail marketing tool used
Log data collected during opening of the Sigrist website via the hypertext transfer protocol (http) for technical reasons
IP address, type and version of your internet browser, operating system used, website accessed, website priorly accessed (referrer URL), date and time of access
Data stored in cookies1 in the browser of our newsletter subscriber when opening the Sigrist website
(»website cookie data«)
Unambiguous ID for identification of the newsletter subscriber
Data in user profiles, that we generate by analysing the user behaviour on our website
(»website user profile data«)
Data on the usage of the website. You can find further information on Google Analytics here.
Independently generated by the Google Analytics tool
Subscriber segments which we generate by combining and analysing newsletter and website user profile data
Data of the interests of the newsletter subscribers relating to Sigrist products and topics
1 Cookies are small text files with information, which are saved on the terminal deviec of the user when they visit a website. In case of further accessing the website with the same terminal device, the cookie and the information stored therein can be accessed.
D. Purpose and legal basis of processing personal data
We process the categories of personal data listed in Chapter C on the legal basis of Art. 6 (1) GDPR for the following purposes:
Purpose of processing
Categories (also see Chapter C) of personal data
Legal basis of processing in accordance with GDPR
Recipient (also see Chapter E)
Provision of web applications on our website enabling you transmit data to subscribe or unsubscribe our newsletter.
Website-http-data, subscription data, registration and deregistration data
Art. 6 (1) ( f)
(for step 1 of registration)
Art. 6 (1) (a)
(for step 2 and 3 of registration)
Art. 6 (1) (b)
(for Sigrist agencies)
Sigrist, newsletter service provider
Double-opt-in process for confirming the newsletter subscription. For this, we send an e-mail requesting confirmation of the e-mail address provided at the registration. Subscription will only be active if the subscriber confirms the e-mail address with the confirmation link contained in said e-mail.
Subscription data, registration and deregistration data
Art. 6 (1) (f)
Newsletter service provider
Forwarding of the newsletter to the newsletter subscribers.
We use the title stated in your registration as well as your name (first name and last name) for addressing you personally in our newsletter.
For determining the language and county-specific content of the newsletter, we use the language, the country and the country-specific version used for registration on the Sigrist-Photometer website.
The company and branch of industry is used for the preparation of company- / branch-specific contents.
Subscription data, newsletter-http-data, newsletter cookie data, website-http-data, segment data
Art. 6 (1) (a)
Sigrist, newsletter service provider
Analysis of the user behaviour of newsletter subscribers in our newsletter and on our website as well as the preparation of user profiles while using pseudonyms as well as subscriber segments based thereon for the purpose of personalization and needs oriented design of the newsletter.
Preparation of anonymised reports for analysing and determining the newsletter strategy
Subscription data, segment data
Art. 6 (1) (f)
Sigrist, newsletter service provider
E. Recipients obtaining personal data
For the purposes described in Chapter D, we disclose personal data to the following service providers or categories of service provider:
Newsletter service provider (simultaneously hosting service provider); for sending our newsletter, we assign a processor. They have committed themselves to us to comply with the valid data protection provisions. A processing contract in accordance with Art. 28 GDPR was concluded. More detailed information concerning the processors can be requested at [email protected].
Sigrist-Photometer AG (also see Chapter A).
F. The period for which the personal data will be stored
The period for which personal data are stored is shown in the following table:
Categories of personal data (see Chapter C for details of the respective categories)
The period for which the personal data will be stored
We comply with the principles of data avoidance and data economy. Thus, we will only store your personal data for such a period as is necessary for fulfilling the purposes mentioned here (see Chapter D) or as is required by the various statutory storage periods. After the respective purpose ceases to apply or after those storage periods expire, the corresponding data shall be locked or deleted routinely and in accordance with the statutory provisions.
Registration and deregistretion data
newsletter cookie data,
newsletter usage profile data
website cookie data,
website usage profile data
G. Necessity or obligation to provide personal data and possible consequences of failure to provide such data
Providing the following personal data are required / compulsory by law or contract or necessary for the conclusion of a contract:
Categories of personal data (see Chapter C for details of the respective categories)
Requirement / Obligation
Possible consequences of failure to provide such data
To receive the newsletter, you have to state your e-mail address in the course of the registration.
Failure to provide the e-mail address has as a consequence that we cannot send you the newsletter.
H. Rights of the data subject
Data access, correction, erasure, restriction and portability
As regards the processing of personal data, you have the following rights:
To obtain access to your personal data in accordance with Art. 15 GDPR,
To obtain corection of your personal data in accordance with Art. 16 GDPR,
To obtain erasure of your personal data in accordance whit Art. 17 GDPR,
To obtain restriction of processing of your personal data in accordance with Art. 18 GDPR,
The right to data portability in accordance with Art. 20 GDPR.
Right to object
You have the right to object in accordance with Art. 21 GDPR, on grounds relating to your particular situation, at any time, to the processing of personal data concerning you which is based on Art. 6 (f) GDPR (see Chapter D).
If personal data are processed for direct marketing purposes (see Chapter D), you shall have the right to object at any time to processing of personal data concerning you her for such marketing.
Right to revoke consent
If the processing is based on Art. 6 (1) (a) or Art. 9 (2) (a) GDPR (see Chapter D), you have the right to revoke your consent at any time without affecting the legality of the processing carried out as a result of the consent until said consent was withdrawn.
Right of complaint at the supervisory authority
You have the right to lodge a complaint at a supervisory authority in accordance with Art. 57 (1) (f) GDPR.