Question and Answer Forum

MISCO Refractometer Q&A Forum

Find answers to many common questions concerning applications, operation, calibration, and maintenance of refractometers:

Battery Maintenance (4)

Which hand-held digital refractometer would be best for checking specific gravity of industrial battery electrolyte (sulfuric acid and water)? Need a minimum range of 1.100 to 1.350.

The Palm Abbe digital handheld refractometer is the best choice for measuring the specific gravity sulfuric acid based battery electrolyte. The range for the specific gravity scale (D20/20) for this refractometer is from 1.000 to 1.501 so it should more than cover your range of interest.

I have a model 10440 Refractometer. My question is what reading should i get for lead-acid batteries at full charge? I currently am reading from 16 to 26 on two different batteries.

The MISCO 10440VP is a great refractometer for testing the concentration of metalworking fluids but it is the wrong instrument for measuring state of charge of lead-acid batteries.

A better choice would be either the MISCO 7084VP+ Glycol and Battery Tester, a handheld traditional analog refractometer with a scale for reading the specific gravity of battery electrolyte, or, the Palm Abbe digital refractometer with scales for sulfuric acid concentration.

There are several sulfuric acid scales available for the Palm Abbe refractometer including, specific gravity, density, and percent by weight. The range for the specific gravity scale (D20/20) for the MISCO 7084VP+ is 1.00 to 1.400 and the range for the Palm Abbe digital refractometer is from 1.000 to 1.501. The Palm Abbe is an order of magnitude more accurate than the 7084VP+.

Could I use a Refractometer to measure the density of flooded batteries. Density is 1.200-1.260?

We have two great tools for measuring the density of battery electrolyte in flooded batteries. The first is the MISCO 7084VP+ Glycol and Battery Tester. The 7084VP+ is a traditional analog refractometer with a scale for the specific gravity of sulfuric acid from 1.000 to 1.400. There are also a number of scales available for the MISCO Palm Abbe digital refractometer that can measure sulfuric acid density, specific gravity, concentration (% by weight) well beyond your range of interest.

Products:
Glycol and Battery Tester ; Ethylene Glycol, Propylene Glycol,  ; Battery Acid Scales  ; Freeze Point °C  Specific Gravity ; MISCO 7064VP+ Refractometer

Glycol and Battery Tester – Ethylene Glycol, Propylene Glycol, Battery Acid Scales   Freeze Point °F Specific Gravity  MISCO 7084VP+ Refractometer

Do you have a digital model for reading the specific gravity of lead acid battery?

The Palm Abbe digital refractometer represents the perfect method for measuring the concentration or specific gravity of the sulfuric acid (H2SO4), or state of charge, in a lead-acid battery. There are several sulfuric acid scales available for the Palm Abbe refractometer including, specific gravity, density, percent by weight. Try our Build-Your-Own section. You can choose up to 5 custom scales!

Brake Fluid (1)

How do you know when to change DOT brake fluid?

It is generally believed that a moisture content of less than 2% is safe for most driving conditions in most parts of the U.S. Conventional wisdom says that a moisture content of 2 to 3% is marginal and that it should absolutely be changed at 3%. You should consult your vehicles owner’s manual or vehicle manufacturer for their recommendations with respect to your specific car. A car generally absorbs about 1% moisture per year of service life. Many motor vehicle companies recommend changing brake fluid every 12-months, others recommend changing every 24-months. The amount of moisture that brake fluid absorbs depends on a number of factors including the type of fluid, humidity, type of brake hoses, condition of the seals and mileage.

Diesel Exhaust Fluid (2)

Do you know of a refractometer that measures the shelf-life of DEF? I’m not as concerned about our contamination as I am the risk. I’ve heard that comes from it sitting idle in a tank for too long.

A Diesel Exhaust Fluid (DEF) refractometer cannot tell you the quality or shelf-life of the DEF, it can only provide you a measure of urea concentration. However, a concentration measurement can tell you if the DEF is over or under concentrated, and may indicate tampering. The MISCO DEF201 and DEF202 digital handheld refractometers can measure the concentration of urea in DEF but this is a measure of concentration only.

Can you use a refractometer to measure DEF Quantity? Is it acceptable practice to add water to adjust over-concentrated samples?

The Palm Abbe digital refractometer (DEF201 or DEF202) can be used to very accurately measure urea concentration in DEF to +/-0.1%. DEF is a composition of ultra-pure urea and demineralized water. ISO standards call for DEF to be 32.5% (+/-0.8%). If your DEF is over-concentrated, due to evaporation, you can add demineralized water to return the measurement to 32.5%. However, you should NEVER add tap water or well water to a DEF. Doing so can cause irreparable damage to your SCR components.

Engine Coolant (1)

We are specifically wanting to measure both Engine Coolant and Windshield Washer Fluid for % concentration and Freeze point. The Coolant is water and Propylene Glycol mixed seeking % Glycol in the mixture. The Windshield Washer fluid is a Methanol and Water mix where they want to know % Methanol. These define freeze point.

The Palm Abbe digital refractometer is the ideal way to measure automotive fluids. The refractometer can be programmed with scales for ethylene glycol (EG) & propylene glycol (PG) engine coolants, methanol for windshield washer fluid, and even brake fluid moisture content. You can select from refractometer scales that display freeze point or concentration for any of these fluids. Use the filters on the Product/Digital Handheld page to select a refractometer with the scales that you need. If you cannot find a refractometer that fits your needs, try the Build-Your-Own Refractometer section or call MISCO customer service. We will be happy to custom program a refractometer for you with the exact scales you need.

Vehicle & Equipment Maintenance (8)

Which hand-held digital refractometer would be best for checking specific gravity of industrial battery electrolyte (sulfuric acid and water)? Need a minimum range of 1.100 to 1.350.

The Palm Abbe digital handheld refractometer is the best choice for measuring the specific gravity sulfuric acid based battery electrolyte. The range for the specific gravity scale (D20/20) for this refractometer is from 1.000 to 1.501 so it should more than cover your range of interest.

We are specifically wanting to measure both Engine Coolant and Windshield Washer Fluid for % concentration and Freeze point. The Coolant is water and Propylene Glycol mixed seeking % Glycol in the mixture. The Windshield Washer fluid is a Methanol and Water mix where they want to know % Methanol. These define freeze point.

The Palm Abbe digital refractometer is the ideal way to measure automotive fluids. The refractometer can be programmed with scales for ethylene glycol (EG) & propylene glycol (PG) engine coolants, methanol for windshield washer fluid, and even brake fluid moisture content. You can select from refractometer scales that display freeze point or concentration for any of these fluids. Use the filters on the Product/Digital Handheld page to select a refractometer with the scales that you need. If you cannot find a refractometer that fits your needs, try the Build-Your-Own Refractometer section or call MISCO customer service. We will be happy to custom program a refractometer for you with the exact scales you need.

How do you know when to change DOT brake fluid?

It is generally believed that a moisture content of less than 2% is safe for most driving conditions in most parts of the U.S. Conventional wisdom says that a moisture content of 2 to 3% is marginal and that it should absolutely be changed at 3%. You should consult your vehicles owner’s manual or vehicle manufacturer for their recommendations with respect to your specific car. A car generally absorbs about 1% moisture per year of service life. Many motor vehicle companies recommend changing brake fluid every 12-months, others recommend changing every 24-months. The amount of moisture that brake fluid absorbs depends on a number of factors including the type of fluid, humidity, type of brake hoses, condition of the seals and mileage.

Do you know of a refractometer that measures the shelf-life of DEF? I’m not as concerned about our contamination as I am the risk. I’ve heard that comes from it sitting idle in a tank for too long.

A Diesel Exhaust Fluid (DEF) refractometer cannot tell you the quality or shelf-life of the DEF, it can only provide you a measure of urea concentration. However, a concentration measurement can tell you if the DEF is over or under concentrated, and may indicate tampering. The MISCO DEF201 and DEF202 digital handheld refractometers can measure the concentration of urea in DEF but this is a measure of concentration only.

I have a model 10440 Refractometer. My question is what reading should i get for lead-acid batteries at full charge? I currently am reading from 16 to 26 on two different batteries.

The MISCO 10440VP is a great refractometer for testing the concentration of metalworking fluids but it is the wrong instrument for measuring state of charge of lead-acid batteries.

A better choice would be either the MISCO 7084VP+ Glycol and Battery Tester, a handheld traditional analog refractometer with a scale for reading the specific gravity of battery electrolyte, or, the Palm Abbe digital refractometer with scales for sulfuric acid concentration.

There are several sulfuric acid scales available for the Palm Abbe refractometer including, specific gravity, density, and percent by weight. The range for the specific gravity scale (D20/20) for the MISCO 7084VP+ is 1.00 to 1.400 and the range for the Palm Abbe digital refractometer is from 1.000 to 1.501. The Palm Abbe is an order of magnitude more accurate than the 7084VP+.

Could I use a Refractometer to measure the density of flooded batteries. Density is 1.200-1.260?

We have two great tools for measuring the density of battery electrolyte in flooded batteries. The first is the MISCO 7084VP+ Glycol and Battery Tester. The 7084VP+ is a traditional analog refractometer with a scale for the specific gravity of sulfuric acid from 1.000 to 1.400. There are also a number of scales available for the MISCO Palm Abbe digital refractometer that can measure sulfuric acid density, specific gravity, concentration (% by weight) well beyond your range of interest.

Products:
Glycol and Battery Tester ; Ethylene Glycol, Propylene Glycol,  ; Battery Acid Scales  ; Freeze Point °C  Specific Gravity ; MISCO 7064VP+ Refractometer

Glycol and Battery Tester – Ethylene Glycol, Propylene Glycol, Battery Acid Scales   Freeze Point °F Specific Gravity  MISCO 7084VP+ Refractometer

Can you use a refractometer to measure DEF Quantity? Is it acceptable practice to add water to adjust over-concentrated samples?

The Palm Abbe digital refractometer (DEF201 or DEF202) can be used to very accurately measure urea concentration in DEF to +/-0.1%. DEF is a composition of ultra-pure urea and demineralized water. ISO standards call for DEF to be 32.5% (+/-0.8%). If your DEF is over-concentrated, due to evaporation, you can add demineralized water to return the measurement to 32.5%. However, you should NEVER add tap water or well water to a DEF. Doing so can cause irreparable damage to your SCR components.

Do you have a digital model for reading the specific gravity of lead acid battery?

The Palm Abbe digital refractometer represents the perfect method for measuring the concentration or specific gravity of the sulfuric acid (H2SO4), or state of charge, in a lead-acid battery. There are several sulfuric acid scales available for the Palm Abbe refractometer including, specific gravity, density, percent by weight. Try our Build-Your-Own section. You can choose up to 5 custom scales!

Washer Fluid (1)

We are specifically wanting to measure both Engine Coolant and Windshield Washer Fluid for % concentration and Freeze point. The Coolant is water and Propylene Glycol mixed seeking % Glycol in the mixture. The Windshield Washer fluid is a Methanol and Water mix where they want to know % Methanol. These define freeze point.

The Palm Abbe digital refractometer is the ideal way to measure automotive fluids. The refractometer can be programmed with scales for ethylene glycol (EG) & propylene glycol (PG) engine coolants, methanol for windshield washer fluid, and even brake fluid moisture content. You can select from refractometer scales that display freeze point or concentration for any of these fluids. Use the filters on the Product/Digital Handheld page to select a refractometer with the scales that you need. If you cannot find a refractometer that fits your needs, try the Build-Your-Own Refractometer section or call MISCO customer service. We will be happy to custom program a refractometer for you with the exact scales you need.