finishing.com -- The Home Page of the Finishing Industry
a Website for Serious Education ...
plus the most FUN you can have in metal finishing.

HomeFAQsBooksHelpWantedsPublic Forum
topic 50132

Salt Spray Test -- ASTM B117 Operational Problems

adv.   auto technology banner


A discussion started in 2003 & continuing through 2017

(2003)

Q. What could be the problem when the condensate collection is not the same for both collecting vessels? The pressure is 12.5 psi and temp is 95 °F. The one closest to the test specimen and to the vents (vents of dispersion tower) collects three times as much as the one farthest from the test specimen and the vents. The collection is always done at 7:30 in the morning (approximately after 24 hours of operation). The pH and specific gravities are within the limits.

Thank you,

Nila O. Par
- Winnipeg, Manitoba, Canada


(2003)

A. Nila,

Inconsistent condensate collection can be caused several different ways depending on the type and model of your salt spray cabinet. Some cabinets allow for slight directional adjustments to provide consistent coverage. Another factor could be that the nozzle could be slightly clogged or a particle caught in the orifice which would result in a misdirected fog. A final possibility could be the nozzle air pressure. Too high a pressure and the fog will spread wider, too low and the fog will settle closer to the nozzle. It may be silly, but you also need to make sure your collection vessels are not placed directly under panels or holding devices which may drip and cause errant readings.

Best of Luck,

Ira Donovan, M.S.F.
Kansas City, Missouri


(2003)

A. Nila -

First I would say that this problem is not unusual. Are you working to ASTM B117 [link by ed. to spec at TechStreet] ? One thing you might try is replacing your filter.

Terry Tomt
- Auburn, Washington, USA


(2003)

A. Nila -

Contact the cabinet manufacturer for suggestions on how to adjust for more even collection rates. Have the following information available: cab temperature, air pressure, humidifying tower temperature, collection rate in each collector. If possible, send them a digital photo. Also, be sure the cabinet is level and properly vented.

Cynthia L. Meade
- Sylvania, Ohio, USA




Concentration of collected solution for salt spray test is too low

March 9, 2008

Q. Dear friend,
I have a question: during salt spray test, the concentration of collected solution is lower than original solution, e.g., the solution I mixed is 5%, but collected solution concentration only about 2%.

What happened to it?

Thanks a lot.

Xie Sophie
- Suzhou, China


March 25, 2008

A. I'm not familiar with any ASTM B117 requirement to run a condensate analysis, but would not necessarily expect the condensate to contain the exact concentration of the bulk solution being aspirated into the (95 °F) tank. You may want to compare your 2% result with the concentration of solution taken from the bottom of the tank and from the "moat" that provides the air-tight seal around the lid.

TRH

Thomas Hanlon
Thomas Hanlon, Materials Engineer
aerospace finishing - East Hartford, Connecticut, USA


March 26, 2008

A. I politely but strongly disagree with Thomas. The analysis only counts on the collected condensate that does NOT drip off of the parts.
If anything, the salt concentration would be expected to be higher in the condensate since the aspiration of the solution would evaporate it.
How are you checking (measuring) the salt concentration?

James Watts
- Navarre, Florida


March 31, 2008

A. Hi

We operate SS chambers per the ASTM and it does indeed require that the collected solution be analyzed for both pH and concentration. You can measure concentration by using specific gravity or by using a salt refractometer. The solution must not have touched any parts and it is not to be taken from the water seal around the lid. There are strict requirements in the ASTM as to how the atomized solution is to be collected.

Thanks,

Terry Tomt
- Auburn, Washington


March, 2008

A. This question intrigued me, so I contacted one of the world's experts on this subject (at a UK salt spray cabinet manufacturer) and this was their reply.

Hello Terry,

The salt solution is mixed with air that has passed through the air saturator, this adds some moisture. The take up of moisture by the air is increased if the air saturator is set to a high temperature. Add to this the fact that the chamber is heated through a base covered in water (to maintain humidity levels) there will be some changes in the concentration of the salt solution.

I would be very surprised if the above would cause the level drop from 5% to 2%.

I would suggest measuring the salt concentration remaining in the salt tank at the end of the test to be sure that the salt dissolved is evenly distributed and that additional water hasn't been added to the tank.

Other than the above, I would suspect a fault with the chamber. Perhaps an overfilling air saturator (causes water to be squirted through the atomizer).

Has the chamber been serviced recently? Are you confident that it is working as it should be?

Kind regards,
Martin

This seems to be a very good explanation as it points to several causes that could contribute to the problem and that are worthy of investigation.

Terry

Terry Hickling
Birmingham, United Kingdom



Our chamber rusts the test parts in too few hours

September 29, 2008

Q. We are just starting up salt fog testing to ASTM B117 and have found some issues regarding pH and premature rust. We think it's related.

Since we are using mixed bed de-ionizers to make type 4 water, we know that it produces a low pH of about 5.5. Once it has been in the tank with Salt for a while, and once it is atomized in the chamber, we get about 6.2.

Not sure what concentration and acceptable grade of NaOH, and HCl to use for adjusting, so we have just kept the chamber running at 6.2. The problem is our chamber is rusting the specimens prematurely. This is of course in comparison with our platers, and other testing facilities. Does anyone think running the chamber on the lower end of the pH range of 6.2 would affect the test this way?

Also, does anyone know what concentration and grades of the HCl and NaOH we should use? And how much to add?

Steven Sherman
Buyer, Final Inspector - Northvale, New Jersey


October 1, 2008

A. A pH of 6.2 is not that acid.

I'd suggest using a freshly calibrated pH probe, and 0.01 N NaOH to adjust the pH to 7.0, if you think that will help. (I don't think it will make much difference, but it won't hurt.)

Insofar as documentation: buy the 0.01 N NaOH from Fisher Scientific, and write the lot number down in a book ... it's hard for me to see how even the toughest auditor could object.

dave wichern
Dave Wichern
Consultant - The Bronx, New York


October 2, 2008

A. Steve,

This sounds very similar to a problem I had a few years back. I used 0.1N analytical grade NaOH and HCl for adjustment. Rather than trying to add a fixed amount and see what happened I would take a 100 ml sample and adjust in the Lab and then multiply up to the reservoir size for the addition. In my particular case it was normally found to require about 50-100 ml of 0.1N NaOH in 120 liters of solution. Once adjusted I would retest the pH of the reservoir and ensure it was between the 6.0-7.0 ^ 6.5-7.2 required by the specification.

By the way, this was related to premature failure of chromate conversion coated samples of 2024 Aluminum.

Brian Terry
Aerospace - Yeovil, Somerset, UK


October 2, 2008

A. Steve,

Isn't the pH on fallout required to be 6.5 to 7.2?

And yes, I would think that a low pH will affect your results.

We use 0.1N reagent grade NaOH or acid to adjust. Make small additions

Terry Tomt
- Auburn, Washington


November 15, 2008

A. You must maintain your collection pH between 6.5 - 7.2 if you wish to perform testing per ASTM B117 (and also avoid false failures and audit findings). Is the sample exposed to open air for any period of time prior to measuring the pH? If so, it may be possible that the solution is absorbing carbon dioxide from air and the pH is decreasing accordingly.

Another question: does your pH meter automatically compensate for temperature differences? If the meter is assuming 77 °F, but your sample is 95 °F, there will be enough error to make you believe you are out of tolerance.

As mentioned before, increase your salt solution with 0.1N NaOH prior to introduction into your chamber. You want to target the higher end of the tolerance since pH of the collected fog will almost always be lower than your salt solution. Also measure with a fresh calibration and a suitable pH electrode/meter. We prefer to calibrate prior to each use.

Terry Lycans
- Dayton, Ohio, USA


November 19, 2008

thumbs up signThe fallout is indeed required to be 6.5-7.2. I think I may be getting my ASTM mixed up with ISO 9227 [link by ed. to spec at TechStreet] for the make up. One of the problems of trying to run a salt spray to multiple specifications!

If there is a continued problem with low pH as collected, the ASTM does allow you to boil the sample for a period to remove the dissolved carbon dioxide. I have tried this before and it does work, but has always felt as if I was fudging the results. Preferable to adjust your reservoir to obtain the correct collected pH.

Brian Terry
Aerospace - Yeovil, Somerset, UK



Specific gravity readings are rising during ASTM B-117 salt spray testing

December 22, 2010

Q. I am having trouble keeping the specific gravity in range, it always seems to be a little high. I use a premixed 5% salt solution, testing the solution before use I get a S.G. of about 1.035 straight out of the drum. After I test the collections I am getting S.G. of 1.045 to 1.050. Could anyone give me an idea of what might be causing the S.G. to raise during the testing?

Shaun Dickenson
Quality Tech. - Frankfort, Indiana, USA

December 23, 2010

A. That is because of the atomization of the solution: some of the moisture and only a bit of the salt goes out the vent.
I always made up my salt solution on the low side so that the condensed salt solution was on spec.
Carbon dioxide caused me a bit of pain in controlling the pH of the collected solution. It required adjustment a couple times a week.

James Watts
- Navarre, Florida



Effect of unbalanced pH Level on Salt Spray Test

March 1, 2011 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread

I'm looking for an answer on the effect of unbalanced pH Level during salt spray testing.
As you know ASTM B117 [link by ed. to spec at TechStreet] requires the collected Salt solution be within pH Level of 6.5 to 7.2, but what if we don't monitor the pH Level of our Salt Spray Testing ... is there a significant effect on our specimen?
We just follow the 5% NaCl mixture solution.

Also, what are different types of Failure or Effect of Salt Spray testing considering all types of specimen? Is there such thing as reference on how to identify the type of Failure or Effect of Salt Spray. I'm still new with Salt Spray Testing and I'm not familiar with other kinds of Failure ... All I know is Red Corrosion or Rust.
I'm even confused between white corrosion and Calcium deposits.

Please advise.
Thanks!

Jem Bernardino
Quality engineer - NSW Australia



A. Hi Jem. We appended your inquiry to an earlier thread which should offer you some insights. See the subheading "Our chamber rusts the test parts in too few hours" above. Good luck.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey


March 4, 2011

A. Hi Jem,

You really need to tell us what you are testing, both base materials and coatings. At the moment it sounds like you are testing on steel, possibly zinc or zinc alloy plated steel?

Anyway the failure to monitor the pH means that you cannot claim to be testing in accordance with ASTM B117. The specification requires that you keep a daily log of the pH from the collectors. So regardless of the effects of pH you need to monitor it anyway.

Brian Terry
aerospace - Yeovil, Somerset, United Kingdom


March 8, 2011

Hi Jem.

1. The corrosion behavior of different platings on different substrates in acidic or alkaline environment are different. Therefore, it is imperative that you maintain pH at 6.5 ~ 7.2 (ASTM B117) to consistently achieve and interpret salt spray results.

2. Interpretation of pass/failure of SST will depend on the standard that the plated part has to adhere to. There is no one reference or standard that covers all. As an example, the mention of white rust and red rust suggests zinc plating on steel substrate. If you are plating to ASTM B633 [link by ed. to spec at TechStreet] ( Standard specification for electrodeposited coatings of zinc on Iron or steel ), it states:

7.4 Corrosion resistance - Zinc coatings with type II and III treatments shall show neither corrosion products of zinc ( white rust - emphasis mine ) nor basis metal corrosion products ( red rust - emphasis mine ) at the end of the test period, as shown below, when tested by continuous exposure to salt spray in accordance to 10.3 .
The appearance of corrosion products visible to the unaided eye at normal reading distance shall be cause for rejection except that white corrosion products at the edges of specimens shall not constitute failure.
Corrosion Resistance Requirement
    Types        Test Period, hours
II 96
III 12
SK Cheah
- Penang, Malaysia


January 10, 2012

thumbs up signThank you for the advice. I am now maintaining the pH Level of the collected solutions and already identified the best pH reading for the Salt Solution in order to have a reading of pH 6.5-7.2 for the collected solution.

Jem Bernardino
- NSW Australia



December 2, 2013

Q. Hi !

I have some problem with the pH of my collectors in my old Harshaw (Auto Technology [a finishing.com supporting advertiser]) salt spray chamber. My salt water solution is around 5% salt, I have to adjust my pH to 8.5 - 9.0 to get 6.50 - 6.60 pH in my collectors. I cleaned my salt water tank, my DI water tower, the chamber itself. All running conditions are good. I just have hard times to get my 6.50 minimum.

My pH-meter is well calibrated, buffers changed regularly, and temperature compensated.

I just don't know where to look anymore. The water is filtered, the salt is ACS. The filtered water is clean, but I have some microbiological contamination in my salt water tank. I'm running a test to see if I've got contamination in my collectors. Can it be caused by that?

Anyway, thank you !

Alex Fournier
Lab Tech - Galvano - Beloeil, Quebec, Canada


December 9, 2013

A. First, empty and scrub your salt water reservoir: it could easily be the biological contamination.
Otherwise, perhaps your feed tubes from the salt reservoir to the bubble tower need to be replaced: tubing is pretty cheap.
The main problem I've encountered with salt spray chambers is copper contamination in the bubble tower coming from the copper compressed air line. The water in the tower acts as a filter, and if you have a greenish-white buildup on the cylindrical casing, you need to dismantle it and get that buildup off. It dissolves easily with paper towels soaked in dilute (25 - 50%) HCl laid on the buildup for about 10 minutes - wipe & repeat if necessary. Though the manufacturers recommendations don't cover it, one should drain and refill the bubble tower once monthly to avoid this possibility.
I don't believe the copper issue has anything to do with altering the pH, but it helps with multiple other problems - like premature or false corrosion of test panels.

Fauna Tester
- Seattle, Washington, USA


February 28, 2014

Q. I scrub my water tank and all but my pH are still low. My salt water reserve has a pH of 9.00, the water coming out of the nozzle is still at 9.00. But the water in my collectors has a pH of 6.50. I cleaned my collectors, changed it for new ones, but the pH is still low. I really don't get it. What could bring down my pH like that? I tried boiling my collected water to remove the CO2 (like in ASTM B117), but nothing.

Any ideas?

Alex Fournier [returning]
Lab Tech - Galvano - Beloeil, Quebec, Canada


March 2, 2014

A. Hi Alex, did you check whether there were drops from the cover falling into your collector? This is impossible if you got correct pH at nozzle but incorrect in your collector; as you know, the fog drops into collector directly and contacts nothing after going out from nozzle. Or did you collect fog with products been tested? If yes, whether there were drops from products fall into collector?

Davey Shaw
Shenzhen, Guangdong, China


December 18, 2014

Q. I has prepared 55 salt solution and I checked the Specific gravity it gives 1.040. But after collection it comes 0.9815. So what is the problem?

B Sankar
- Hyderabad,Telangana, INDIA


A. Hi Sankar. Although I haven't run a salt fog cabinet, I think it's some kind of measurement error. The specific gravity of pure water is 1.00 and it should be heavier with any salt in it.

Regards,

pic of Ted Mooney
Teds signature
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey
Striving to live "Aloha"



Very high mass lost in salt spray test

May 8, 2015

Q. I have completed the panel testing in my Harshaw (Auto Technology [a finishing.com supporting advertiser]) salt fog cabinet (96 hours following ASTM B117) and my results for loss of mass are extremely high at 7.22g of mass lost! I have good pH, specific gravity, level 4 DI water, and using a 5% NSS. Any insight as to why the loss is so great?

Tonya Moses
- detroit, Michigan USA


May 12, 2015

A. Tonya,
Use a calibrated temperature probe to verify that you are 95 °F. (A 10 °C increase in temperature will double the rate of corrosion.)

Dan Mack
- Horicon, Wisconsin



Salt Spray cabinet collectors are collecting more than the required amount

September 10, 2015

Q. Does anyone know the affect/ effect of running a salt-fog cabinet at 2 ml fog collection per hour versus 1 ml/ hr? With all other variables the same. Does it make a difference on corrosion of parts?

David Entrekin
- Madison, Mississippi, USA


September 16, 2015

Q. Recently, our Salt Spray cabinet collectors have been collecting more than they should. The collector closest to the chimney has been collecting over the required amount for several days regardless of the position of the atomizer. The other collector is within specification, but is also collecting more than usual. The pH has been within spec as well. The plant air pressure has not gone up, either. How do I reduce the amount in the collectors? What am I missing? Any help would be greatly appreciated!

Thanks,
Scott

Scott Acosta
Quality Auditor - Agawam, Massachusetts


September 23, 2015

A. Adjust (lower) the pressure regulator on the airline.

Fauna Tester
- Seattle, Washington USA


December 18, 2015

Q. My pH is fine, making up my own solution. Unfortunately the Specific Gravity keeps rising. How do I get it back under control and keep it there? I've lowered the amount of salt but it's still reading 1.047 as of today.

Kay Lane
- Hazel Park, Michigan USA


December 30, 2015

Q. NEED HELP PICKING A SALT SPRAY CHAMBER
Anyone had any experience with Inland salt spray testing chamber Model WTS 90. I'm trying to decide between it and Singleton

James Langley
- Opp, Alabama United States


December 2015

thumbs up signHi James. Hopefully readers will discuss general aspects of salt spray chambers with you but, sorry, comparing brands is something that we have found to be incompatible with this site :-)

Most of the people posting here are real, but the semi-anonymity of the internet has allowed shills to post with fictitious names, posing as satisfied customers :-(

Plus, it has led to rancorous threads instead of camaraderie, and encouraged spam. Apologies, but we do not post brand comparisons on the site anymore. But we hope you will also consider Auto Technology [a finishing.com supporting advertiser] for your salt spray chamber needs. Good luck.

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey
Striving to live "Aloha"



Salt spray cabinet problem: Blue buildup on atomizers

June 7, 2016

Q. We are running a ASTM B117 salt spray chamber, recently I have seen a blue color build up on the atomizers. I clean everything and the next day it has build up again.

Does anyone know what could be causing this? I been running the salt spray testing for about a year and never seen this before.

Dave Clouse
- Monroe, Michigan USA


June 15, 2016

A. My guess would be copper contamination, probably from the air lines. Take an air filter off the line & swap the interior of the connecting pipe to check. If there's buildup, replace your piping. Also drain & clean your bubble tower, as it acts as a filter & gets contaminated.

Fauna Tester
- Seattle, Washington USA



June 29, 2016

Q. We often test large panels (10-15" in height) and smaller panels (6") at the same time in our Q-Fog chamber. Is there any concern that there is a "shadowing" effect if large panels are places in front of small panels? Or even between the large specimens placed next to each other?

Olivia Isaac
- Sunnyvale, California


June 30, 2016

A. Good day Olivia.

I too, had the same concern as I had designed racks for panels some years ago, and had arbitrarily chosen 1.5 inches separation based on monthly panel requirements and square footage of cabinet area.

According to NADCAP regulations regarding salt panel separation:

"10 inch panels @ 6 degrees from the vertical shield approx. 1.0 inches."
"6 inch panels @ 15 degrees from the vertical shield approx. 1.6 inches."

See ASTM B117-11, Section 7 "Position of Specimens During Exposure."
Hope this helps.
From a fellow salter.

Regards,

Eric Bogner, Lab. Tech
Aerotek Mfg. Ltd. - Whitby, Ontario, Canada


July 5, 2016

Q. Thank you Eric. Could you point me toward the Nadcap documentation? I'm not familiar with it, only ASTM B117.

Thank you,
Olivia

Olivia Isaac [returning]
- Sunnyvale, California, USA


July 14, 2016

A. Good day Olivia.

Google "NADCAP Website" for programs, info...
There is a contact available.

Regards,

Eric Bogner, Lab. Tech
Aerotek Mfg. Ltd. - Whitby, Ontario, Canada



September 19, 2016

Q. Should the salt spray cabinet be in a controlled temperature room and not inside a warehouse where the temperature and humidity varies from season to season?

Raul delarosa
chemicals - Whittier, California USA


November 16, 2016

Q. Has anyone used the adjustable angle panel rack available (ACC16/VARIABLE/450/1000/2000L) from Ascott? All of my salt fog panels have to run at 6-deg and I see a variety of panels thicknesses.

Wil Barwick
- Charleston South Carolina


November 16, 2016

Good day Wil.

What a novel idea about the rack.
The only problem I can foresee, is Nadcap salt panel separation requires "10 inch panels @ 6 degrees from the vertical shield approx. 1.0 inches", and "6 inch panels @ 15 degrees from the vertical shield approx. 1.6 inches".
I had my racks fabricated and designated to accommodate variations in panel thicknesses.
Some Nadcap auditors do go to EXTREME length to discover observations, minors, and the dreaded majors.

Regards,

Eric Bogner, Lab. Tech
Aerotek Mfg. Ltd. - Whitby, Ontario, Canada


HELP! Q FOG ISSUE

June 23, 2017

Q. I have a Q Fog CCT corrosion chamber, 600 and ever since I cleaned all of the lines and filters the collection rate has tripled (6 ml/hr). I am running ASTM B117 salt spray. Anyone ever have this issue? Could it be the spray nozzle itself is worn out? The cabinet is 10 years old

Sandy Mitchell
Employee - Louisville, Kentucky USA
  ^- Privately contact this inquirer -^



July 8, 2017

Q. I'm having issues with the collected salinity level vs. the brine in the supply tank. I'm dead on 5% in my supply tank(use pre-mix solution), but my collection level is at 7%(out of spec per DO-160).
I had my pressure for the tower at 12psi & my collection rate was < 1 mL/hr, so I increased to 14 psi and now the salinity increased.

Been running the same test & settings for years, we do total PM's & cleaning prior to start. Just ran a test a few months ago setup was the same with no issues.

What are the affects of increasing/decreasing psi vs. collection salinity level?
Thanks

Ray Horvath
Honeywell Aerospace - Tucson, Arizona, USA



July 31, 2017

Q. I run a SST in the labs where I work. The chamber drains to a floor drain.

Ever since we have had it, fog is escaping constantly from the floor drain.

It is either refogging in the drain and coming back out or it is just fog going down and out the chamber drain.

Basically salt gets everywhere if we leave our floor drain uncovered and if we cover it, then we get tons of back pressure issues.

Has anyone else had problems like this?

Thanks!

Kyle Schmitt
Caterpillar - Peoria, Illinois, USA


August 7, 2017

A. Hello all!

Sandy: I hope you solved this already, but if you haven't, I think the fog ejector may have some regulation (bigger or smaller drops, more or less salt water injection). If not, you may need to do it by modifying air pressure in the ejector.

Ray: Do you pre-humidify the air you inject? There is a saturation tower in almost every design of SST, so the air you inject is 100% relative huimidity at 40 °C (it is my setting). You should verify this point! Let us know if you solved this!

Kyle: Does the chamber have a vent? If not, it is a design failure ... Almost every chamber I've seen has one to evacuate excess fog and balance pressures. You can drill a hole and put some pipes up to the roof, and it may serve you as well.

Hope you can solve your issues! Best regards!

Daniel Montanes
TEL - N FERRARIS - Canuelas, Buenos Aires, Argentina


August 8, 2017

Q. Daniel.

Thanks for the reply!

We do have roof venting. The company makes a power fan to assist ventilation and now we are going to run a wet bottom in the chamber.

So fog is being helped out vent to relieve pressure by fan and there is a water layer at bottom of chamber to prevent fog from leaking out drain tubes.

Thanks.

Kyle Schmitt [returning]
Caterpillar - Mossville, Illinois, USA


August 11, 2017

A. Hi Kyle,

Well, the water layer at the bottom must be at least above the drain pipe level so it prevents fog leakage through it.

Try to maintain this valve closed and open it only to drain when the liquid is too high. We have this valve open but it goes right into a big equalization wastewater tank for treatment, so we don't really see any fog here in the lab.

You mustn't have any problem with this, because the pressure must be relieved through the roof venting. If it isn't, then you have some obstruction in it.

Hope you solve this issue! Regards,

Daniel Montanes
TEL - N FERRARIS - Canuelas, Buenos Aires, Argentina



This public forum has 60,000 threads. If your question seems off topic to this thread, you might prefer to search the site:

ADD a Q or A to THIS thread START a NEW THREADView This Week's HOT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices


©1995-2017 finishing.com     -    Privacy Policy
How Google uses data when you visit this site.