You should always refer to the meat cooking chart and follow the FDA guidelines for cooking meat to specific temperatures. The only true way to know if the meat is undercooked is with an instant read thermometer. Without one of these, you are guessing, and guessing isn’t part of the temperature chart for cooking. Always refer to the cooking temperature chart and make sure you have an instant read thermometer to check temperatures.

Rare lamb is actually the Chefs preferred way to serve lamb, not everyone likes rare, 125⁰F, but most people will eat a medium rare lamb chop. Two things about cooking lamb rare which are important when deciding what temperature range to cook the lamb to. First is lamb cooked rare has a milder flavor because the fat in the chops hasn’t melted and incorporated into the meat, second is the meat hasn’t cooked long enough for the protein strands to shrink and solidify, making a more tender chop. If you can eat it rare, I recommend you do so, if you can’t, then don’t cook it past medium rare, and pull it as soon as it gets to temperature.

Infrared thermometers do not “see through” glass, liquids, or other transparent surfaces even though visible light (like a laser) passes through them—i.e. if you point an IR thermometer out a window, you will be measuring the surface temperature of the window itself.

No. Infrared thermometers can only measure the surface temperature of water.

The “spot size” of any given measurement is controlled by two variables:

The distance-to-target ratio (or spot ratio) of your particular infrared thermometer
The distance between your infrared thermometer and the target
Typically listed on the thermometer itself, the distance-to-target ratio (DTR) – or spot ratio – tells you the diameter of the circle of surface area an IR thermometer will measure at a given distance.

For example, an infrared thermometer with a 12:1 DTR ratio will measure the temperature of a 1-inch diameter circle of a surface area from 12 inches away.

To be accurate, infrared thermometers must be kept free of dirt, dust, moisture, fog, smoke, and debris. Always take the time to clean your infrared thermometer after exposure to dirty, dusty, smokey, or humid conditions. You should also plan a regular cleaning every six months or so. Particular care should be taken to keep the infrared lens and tunnel clean and free of debris.

To clean your infrared thermometer:

Dip a soft cloth or cotton swab in medical alcohol (never use soap or chemicals).
Carefully wipe the lens first and then the body of the thermometer.
Allow the lens to dry fully before using the thermometer.
Never submerge any part of the thermometer in water.

It depends upon the particular model of infrared thermometer. Consult the user’s manual that came with your thermometer for the full range of features and how to use them.

Substances with very low emissivity ratings, like highly-polished metals, tend to be very reflective of ambient infrared energy and less effective at emitting their own electromagnetic waves. For example, if you were to point an infrared thermometer with fixed emissivity at a stainless steel pot, the reading will be incorrect because shiny metal is better at reflecting the ambient radiation of the room than it is at emitting its own infrared radiation.

Some infrared thermometers have fixed emissivity settings (usually of 0.95 or 0.97) to simplify their operation while leaving them suitable for most organic materials, including almost all foods. Other infrared thermometers come with adjustable emissivity settings, so you can more accurately prepare your thermometer for the type of surface being measured, particularly when measuring non-organic materials.

Infrared thermometers can be calibrated for accuracy, just like other thermometers. In calibration labs technicians use industrial black bodies (like the IR-500 Portable IR Calibrator) to calibrate infrared thermometers.

The primary use of infrared thermometers is in measuring the temperature of a subject from a distance. The device is beneficial in situations where it is difficult to reach the object to record the temperature.