ETI Mini RayTemp Infrared Thermometer

ETI Mini RayTemp Infrared Thermometer

Non-contact surface temperature checks with laser alignment

The ETI Mini RayTemp is a handheld infrared thermometer for surface-temperature measurements. Aim at the target and press the trigger to take a reading on its backlit display. It measures from -50 to 330°C and includes laser-dot alignment to help position the measurement area.

Product details

What an infrared reading tells you around a pond

The Mini RayTemp measures the surface within its field of view. This makes it useful for appropriate surface checks where touching the target is inconvenient, but it does not tell you the temperature of pond water below the surface. If your main purpose is to monitor the water occupied by the fish, choose an instrument with a suitable immersed sensor for that job.

It is also important to distinguish surface temperature from air temperature. Pointing at a filter housing, for example, measures the visible housing surface; it does not establish the temperature inside the filter. Decide which temperature you actually need before taking a measurement, and record the target as well as the displayed number so that later comparisons remain meaningful.

Taking a reading and using the hold function

Connect the supplied battery in the compartment inside the handle. Aim at a suitable target and squeeze the trigger: SCAN appears while the thermometer measures. Releasing the trigger changes the display to HOLD, retaining the reading for ten seconds before automatic shutdown. This gives you a short opportunity to record the result without keeping the instrument aimed at the target.

ETI warns that holding the trigger for a prolonged period can affect the displayed reading. For repeat checks, use a consistent position and technique instead of assuming that a longer trigger press improves accuracy. If the measured temperature is outside the instrument’s range, Lo or Hi replaces the numerical result; normal readings return when the target is within range.

Understanding the 12:1 measuring area

The optical ratio describes the relationship between distance and the diameter of the area being measured. At a distance of 60cm, the Mini RayTemp reads an area approximately 5cm across. The area grows as you move away, so a small component can become mixed with its background in the reading. Move closer when the intended target is smaller, while keeping a safe working position.

The laser helps with alignment; it is not the temperature sensor or the boundary of the measuring area. The Mini’s pointer operates with the trigger and cannot be switched off independently. Avoid aiming it towards anyone’s eyes, including fish or other animals. ETI’s general infrared guidance also recommends viewing the surface squarely and allowing the instrument to adjust to the surrounding temperature.

Accuracy, resolution and suitable surfaces

The display resolves changes of 0.1°C or 0.1°F, but that decimal place is not a claim of 0.1-degree accuracy. ETI specifies accuracy of ±2°C from 0 to 330°C. Below zero, the stated tolerance is ±4°C or ±4% of the reading, whichever is greater. Consider that tolerance when deciding whether a small difference between two displayed values is useful for your application.

Emissivity is fixed at 0.95 on this model. It cannot be adjusted for different target materials, and ETI does not recommend infrared measurement of shiny or polished metal. A doubtful reading from reflective equipment should therefore prompt a check of the measurement method, rather than an immediate conclusion that the equipment has changed temperature.

Changing units and replacing the battery

The Celsius/Fahrenheit selector is inside the battery compartment; Celsius is the default. Select the units you want before starting a set of readings, then use the same units in your log. The backlit display includes a low-battery indicator, and the instrument uses one 9V PP3 battery. ETI lists a continuous-use battery life of 80 hours.

Replace the battery promptly when the warning appears. The manual explains that the thermometer can continue operating with the warning visible, but a fresh battery is needed to maintain accuracy. This is a separate issue from an out-of-range Lo or Hi message, so check which indication is actually on the screen before troubleshooting.

Keeping the optics clean and storing the instrument

The sensor lens is delicate. Keep the opening protected from dirt and do not insert objects into it. ETI’s infrared care guide recommends cleaning the lens only when necessary, using extreme care with a very soft cloth or cotton swab and water, then allowing it to dry completely. Avoid soap and chemicals. Never immerse any part of the thermometer.

The Mini instructions specify storage between 10 and 40°C. Keep it dry and protected from knocks between uses. A move between markedly different environments can affect infrared readings, so let the thermometer acclimatise before judging an unexpected result. Moisture or condensation on the optics is another reason to pause and check the instrument rather than trusting the first number displayed.

Adding temperature to your pond records

Temperature is one part of pond monitoring. The NT Labs Pond Lab Mini Test Kit provides separate pH, ammonia and nitrite checks; none of those readings can be obtained with this thermometer. Record each measurement with its method and location so that a surface reading is never mistaken for a water sample taken at depth.

The ETI Mini RayTemp operating instructions cover this exact 814-080 model. Follow those instructions for operation and care, particularly when comparing it with other RayTemp instruments that have different ranges, controls or probe connections.