Rhopoint Novo-Gloss Gloss Meters

• Data

  Measurement	20° High Gloss FInishes	45° Speciality Angle	60° All Gloss Finishes	85° Low GLoss Finishes	Haze (11523)
  Range (GU):	0-100 100-2000	0-100 100-1000	0-10 10-100 100-1000	0-100 100-199	(Log HU) 0-500
  Repeatability:	0.2 (GU) 0.2 %		0.1 (GU) 0.2 (GU) 0.2%	0.2 (GU) 0.2 %	(Log HU) 1
  Reproducibility:	0.5 (GU) 0.5 %		0.2 (GU) 0.5 (GU) 0.5 %	-	(Log HU) 10
  Resolution (GU):	0.1
  Measurement Area:	6.0 x 6.4 (mm)	8 x 12mm ellipse	6.0 x 12.0 (mm)	4.4 x 44.0 (mm)	6.0 x 6.4 (mm)
  Standards:	ISO 2813, ASTM D523, ISO 7668, ASTM D2457, IN 67530, JIS Z 8741	ASTM D2457, ASTM C346	ISO 2813, ASTM D523, ISO 7668, ASTM D2457, IN 67530, JIS Z 8741		ASTM E430, ASTM D4039
  General
  Battery Type:	Rechargeable lithium ion
  Operation (hours):	17+
  Readings per Charge:	20.000+
  Memory:	8MB, 2,000 readings
  Operating Temp:	15-40°C (60-104°F)
  Operating Humidity:	Up to 85%, non condensing
  Dimensions & Weights
  Dimensions:	65mm x 140mm x 50mm (H x W x D)
  Instrument Weight	390 g
  Packed Weight:	1.6 kg
  Packed Dimensions:	110mm x 280mm x 220mm (H x W x D)
  Applications
  Paints and Coatings, Yacht Manufacturers, Automotive Re-finish, Smart devices (PC & Laptop Covers), Furniture, Metal Polishers, Polished Stone, Wood Coatings, Automotive, Printed Cartons, Plastics Industry, Printing Ink, Aerospace, Detailing, Textile, and Powder Coating

Why Measure Gloss? The gloss level of an object is one of the visual attributes used by a consumer to determine whether or not that object is fit for purpose. For example, if the gloss measurement is too high the surface is extremely shiny, too low a possible dull finish. Gloss Measurement has been defined as "The measurement of the attribute of surfaces that causes them to have shiny or lustrous, metallic appearance." Manufacturers design their products to have maximum appeal: from highly reflective car body panels to glossy household appliances or matt finish automotive interior trim. This is especially noticeable where parts may be produced by different manufacturers or factories but will be placed adjacent to one another to create the finished product. Therefore it is important that gloss measurements are taken to insure that consistent gloss levels are achieved on every product or across different batches of products. Gloss can also be a measure of the quality of the surface, for instance a drop in the gloss of a coated surface may indicate problems with its cure, leading to other failures such as poor adhesion or lack of protection for the coated surface. The gloss of a surface can be greatly influenced by a number of factors, for example the smoothness achieved during polishing, the amount and type of coating applied or the quality of the substrate. It is for these reasons that many manufacturing industries monitor the gloss through gloss measurement taken with a glossmeter of their products, from cars, printing and furniture to food, pharmaceuticals and consumer electronics.

How is Gloss Measured? Gloss measurements are taken by shining a known amount of light at a surface and quantifying the reflectance. The angle of the light and the method by which the reflectance is measured are determined by the surface material and which aspect of the surface appearance is to be measured.

Which angle should I use for my application? ISO 2813 and ASTM D523 (the most commonly used standards) describe three measurement angles to measure gloss across all surfaces. Gloss is measured in gloss units (GU) and is traceable to reference standards held at NIST (USA).

Universal Measurement Angle: 60° - All gloss levels can be measured using the standard measurement angle of 60°. This is used as the reference angle with the complimentary angles of 85° and 20° often used for low and high gloss levels respectively.

Low Gloss: 85° - For improved resolution of low gloss a grazing angle of 85° is used to measure the surface. This angle is recommended for surfaces which measure less than 10GU when measured at 60°. This angle also has a larger measurement spot which will average out differences in the gloss of textured or slightly uneven surfaces.

High Gloss: 20° The acute measurement angle of 20° gives improved resolution for high gloss surfaces. Surfaces that measure 70GU and above at the standard angle of 60° are often measured with this geometry. The 20° angle is more sensitive to haze effects that affect the appearance of a surface.

Speciality Measuring Angle: 45° This measuring angle is in accordance with the ISO 2457 standard for the gloss measurement of plastic films and solid plastic parts as well as according to the standard ASTM C346 for the gloss measurement of ceramics To quantify haze, distinctness of image, reflected image quality and other surface texturing please consider the Rhopoint IQ.

Haze Measurement - Haze can be described as near specular reflection. It is caused by a microscopic surface structure which slightly changes the direction of a reflected light causing a bloom adjacent to the specular (gloss) angle. The surface has less reflective contrast and a shallow milky effect. In the coatings industry, this microscopic surface texture is often due to poorly dispersed raw materials, incompatible raw materials or oxidation and weathering. For polished metal surfaces, haze is often associated with polishing marks or chemical residue.

Haze - Haze is light that has been reflected by small surface structures adjacent to the main specular component. Reflectance haze - An optical effect caused by microscopic texture or residue on a surface.

Reflection Haze - Reflection haze is an optical phenomenon usually associated with high gloss surfaces. It is a common surface fault that reduces appearance quality. A hazy surface has a visibly shallower reflection with a milky finish and halos appear around reflections of strong light sources. A high gloss finish with haze exhibits a milky finish with low reflective contrast and reflected highlights. Lowlights are less pronounced. On surfaces with haze, halos are visible around the reflections of strong light sources.

Causes of Haze 

• Coating & Raw Materials - Dispersion, Pigment properties, Particle size, Binder compatibility, Influence and migration of additives, Resin types and quality
• Curing - Drying conditions. Cure temperature
• Post Coating - Polishing marks, Cleanliness, Ageing and oxidisation

Novo-Gloss with Haze - Gloss and Haze Measurement with Array Technology - The 20/60/85 Novo-Gloss Gloss Meter with haze uses a 512 element linear diode array which profiles reflected light in a large arc from 14° to 27°. The instrument processes this high resolution data, selecting individual elements within the array that equate to the angular tolerances outlined in international measurement standards.

In a single 20° measurement, the calculations made are pictured below:

Gloss =

Σ Pixels between 20°±0.9° (sample)
________________________________

Σ Pixels between 20°±0.9° (standard)

Haze = 100*

Σ Pixels from 17° to 19° (sample)+
Σ Pixels from 21° to 23° (sample)
________________________________

Specular Gloss (Standard)

logHaze = 1285(log10((Haze/20)+1))

Curved Surface Advantage - A major advantage of the 20/60/85 Novo-Gloss Gloss Meter with haze is that it automatically compensates for curved or textured sample surfaces by virtually adjusting the measurement position. Conventional gloss haze meters have fixed optics which can make measurement unreliable as any sample curvature will reflect light away from the center of the measurement sensor causing errors. The Novo-Gloss 20/60/85 version with haze automatically adjusts the sensor position by detecting the peak of the reflected light. The laws of reflection state that the incident angle is equal to the reflection angle thus the peak equates exactly to the 20° gloss angle.

Diffuse Corrected Haze with Array Technology - Reflection haze is caused by micro texture on a surface which causes a small amount of light to be reflected adjacent to the gloss angle. For white surfaces, bright colors and metallics, a certain amount of diffuse light, reflected from within the material, is also present in this region. This diffuse light exaggerates the haze signal for these surfaces causing higher than expected readings. * Only enabled when the instrument is set to haze measuring mode of ASTM E430 The 20/60/85Novo-Gloss Gloss Meter with haze compensates for reflection from within the coating for highly reflective pigments, metallic coatings and specialty pigments, allowing the haze of any painted surface to be measured.

Corrected Haze on Metallic Coatings - For non-metallic surfaces, the diffuse component is Lambertian: It is equal in amplitude at all angles in relation to the sample surface. Conventional gloss haze meters measure diffuse reflection using a luminosity sensor positioned away from the gloss angle. Luminosity is subtracted from the haze signal allowing non-metallic surfaces to be measured independently of their color. Gonio photometric information profiling the reflection from white, grey and black panels with an identical topcoat. The 20/60/85 Novo-Gloss Gloss Meter with haze captures compensation information from a region adjacent to the haze measurement angle. This means it can be used on metallic coatings which reflect light. An advantage of the Novo-Gloss 20/60/85 version with haze is that unlike a conventional instrument, compensation is calculated using a region adjacent to the haze angle. This technique gives compatible readings on solid colors but also compensates for directional reflection from metallic coatings and specialty pigments.

Certified calibration tile with certificate, USB data cable, Wrist strap, Novo-Gloss Multi Gauge software, Instructional videos, USB data stick (with Instruction manual, BT wireless data app, Example Excel spreadsheets)