Objective Data re: Record Cleaning

To objectively measure the efficiency of a cleaning process, you always start with a known contaminated standard and then measure how much of the contaminates were removed.  This is generally accomplished with parts of a specific area and weight with a known weight of standardized soil applied, and pre and post weights are compared being one criterion, another being a wash with a powerful solvent to measure non-volatile residue (NVR) and another being a particle count.  High magnification could also be used, but the inherent problem is field of view - you end up looking at a very, very small area.  For large surface areas, and complex geometries (i.e., a grooved record) often statistical measure are applied based on allowable contamination (NVR & particles) per sq-ft or sq-in or for semi-conductor chips much smaller with crazy NVR and particle count requirements.

But the record presents a unique situation since every inch represents valuable data.  So, a small area sample would likely not be representative requiring a larger area which then adds a lot of complication to the test.  Record contamination with hard non-viscous detritus (such as a particle) can cause the ticks and pops, but soft viscous detritus (such as a cleaner residue) can cause loss of high frequency information.  

If you read this article on UT, pay attention to the particle cleaning efficiency between 40-kHz and high kHz - awad-reprint II (crest-ultrasonics.com); Recent investigations have confirmed that higher frequencies are more effective for the removal of certain contaminants.  Reports on particle removal efficiency have shown that the removal efficiency of one micron and submicron particles in deionized water has increased with the higher frequency. At 65 kHz, the
removal efficiency of a one micron particle is 95 percent, versus 88 percent at 40
kHz. A similar increase in efficiency results was reported for 0.7 and 0.5 micron particles. 

If you did a rigorous record cleaning test, you would more than likely find that there were efficiency differences in any single step with different equipment and different chemistry but combined in a process of pre-clean & final clean they could all yield very high cleaning efficiency with only small differences at the higher end with higher end not necessarily defined by the most expensive process.  A lot of expense is for convenience.

Just some thoughts.

PS/Precision cleaning processes, cleaning efficiency and cleanliness verification is something I did for the Navy for 20-yrs for high pressure oxygen (and other compressed gases) and life support systems.  

I don’t think that weighing records pre and post will tell us much.

Since these particles are so small I am not sure how useful studies showing more or less sub 100 micron particles have been removed are.  It might mean something but it would be awfully difficult to control for small particle contaminants pre and post clean.   
  What truly matters to me would be how the record sounds.  That is why I am wondering if there is any objective measure-such as pops and clicks- to go by.
  

When measuring weight, the samples are measured to <0.01 mg and particle counts below 50-micron are normal noting that the nominal width of the groove (at the top) is 50-microns.  

Otherwise, Parks Audio phono-preamps Parks Audio (parksaudiollc.com), the current WAXWING and the older PUFFIN both have a Grade feature parksaudiollc.com/waxwingmanual.html and C:\Users\parks\AppData\Local\Temp\mso6045.tmp (parksaudiollc.com) - This function determines a letter grade for an album side based on scratches, vinyl surface noise, and groove wear. It works best in conjunction with your own ears.  You can do before and after.  However, how the Grade feature functions is unknown, and once you introduce "how it sounds" that's subjective, leaving you with the many current reviews and opinions.

It seems to me that the particles that will interfere with playing may be so small that frequently their mass may be immeasurable.  A vey tiny piece of dust may become wedged in a groove at just the right angle to deflect a cartridge temporarily.  Those dust particles may have accumulated over multiple playing and then over the years become deeply embedded.  Their removal may improve replay but if they weigh a millionth of a milligram I wouldn’t trust any pre and post clean weight of either the lp or the cleaning solution. 
  What makes more sense to me would be a digital graph of the waveform produced as the stylus traverses the record.  It should be possible to find deflections caused by debris.  It should also be possible to correlate noises heard by listeners, such as pops and clicks, to a deflection on the graph.

  It then should be possible to do the following test.  Take 200 LPs.  Play prior to cleaning and measure the events.  Perhaps the average will be 3 of these events per side.  Clean half the LPs with a machine such as Degritter and the other 100 ultra sonically.  Hypothetically, the former will reduce the events to 2 per side, and ultra sound to 1 per side.  Or not.

  This to me would be more meaningful than comparing pre and post weights.  Even if these weights could be measured accurately, there is always the possibility that the Delta in the weight is due to musically irrelevant factors.  For example, what if one of the technologies is more prone to remove some vinyl from the edge of the recording before any music is playing?  I am more interested in what happens in the grooves

The weight I was referring to was of smaller coupons that represented a record contaminated with a known amount of soil only to measure cleaning efficiency - not the entire record. Otherwise, there are lab techniques that can be used to measure non-volatile residue (NVR) such as left-over cleaner in the range of mg/sq-ft and techniques that can do a particle count. In the precision cleaning industry, there is a cleaning standard called Level 50A. It’s about the cleanest you can achieve in a residential environment and the requirements are:

NVR - not more than 1-mg/sq-ft which if uniformly applied to the surface of a record which is about 1-sq-ft equals a film thickness of 0.1-micron.

>5 <15-microns.....166 particles
>15 <25-microns....25 particles
>25< 50-microns.....8 particles
>50-microns............1 particle

Edit;  There are digital electronic microscopes such as olympus-ims.com/en/.downloads/download/?file=285216326&fl=en_US&inline that can 3D map a surface.  The problem is field of view - you are looking at only a very small area.   But if a standard 'record coupon' say 4-sq-in was developed and contaminated with a standard soil, a measure of cleaning efficiency could be determined.

Otherwise, there is software that some people use to such FFT Sound Analyzer - Audio Analysis Software - Windows & Mac (nch.com.au) that can analyze the before and after to ’measure’ the improvement made by cleaning which is essentially what the Parks Audio Grade feature can do. You can reclean a record with the same machine or process and if there is no further improvement, it really only means that you have reached the limits of that machine/process.

But, absent a criterion for what is a clean record, it becomes subjective. The real differentiation is how clean is it relative to a cleanliness standard. Absent the standard and a way to effectively and reasonably measure it against that standard, inevitably, how clean is the record becomes subjective to how it sounds, which may not reflect how it could sound.