Hello,
Thank you for your post, I'm sorry to hear about the trouble your having with your refractometer. These are very accurate and reliable products. If you haven't done so already you will need to calibrate your refractometer periodically.
To calibrate it, take a reading using distilled water (if possible "“ the temperature needs to be about 68° F). With distilled water on the prism, turn the calibration screw with the included screwdriver while looking through the eyepiece until the boundary line falls on "œ0". This will ensure you are getting an accurate reading
A word of precaution the salinity refractometer is an optical tool "“
- do not drop it or handle it roughly.
- do not use a rough or abrasive material to clean the prism.
It best not to compare a refractomer with a convectional hydrometer due to air bubbles that tend to stick on the measurement arm
Please let me know if you are successful getting an accurate reading
Best regards,
Walter
Marine Depot Customer Service