LaMotte
LaMotte ColorQ photometers: what the 2x PRO 7 measures, the check kit that proves the meter still reads true, and what the warranty leaves out.
Test kits
Before you buy LaMotte
A meter you can actually check
The question with any photometer is whether it still reads true, and most consumer meters give you no way to answer it. LaMotte publishes one: the ColorQ and ColorQ 2x Performance Check Kit, code 4301, which holds a 60 mL Performance Check Standard (4302-H) and tubes for both meter generations.
The procedure is worth understanding before buying a meter, because it only works if you start early. You run the standard once when the meter is new and record that as the initial reading. Later checks compare against it, and the meter passes if it lands within plus or minus 0.30 on a ColorQ 2x — 0.35 on the original ColorQ. LaMotte suggests re-checking at intervals set by use, for example after ten hours.
Two practical limits. The standard has a six-month shelf life, and it is read as free chlorine, so the check verifies the meter's optics and chamber rather than every reagent in the kit. Do not pour the standard back into the bottle, and keep it cool and out of light.
What the warranty covers, and what it leaves out
LaMotte's user guide gives one year on ColorQ 2x parts and workmanship, and asks you to keep proof of purchase for warranty verification. It does not mention the reagents, which is the usual position for consumables and the reason a meter's running cost sits outside its warranty entirely.
LaMotte Company is in Maryland, and publishes the instruction manual, the user guide and the check kit manual as separate documents. The user guide is the one carrying the interferences and cleaning notes; the instruction manual carries the test procedures. Where a photometer fits against a drop kit is the decision behind all of it.