Selection Guide

Response time determines how quickly an infrared thermometer can follow changes in surface temperature. For stationary or thermally stable objects, it may have limited practical impact. For moving targets, rapidly heating components, or continuous production processes, a faster response can help capture temperature changes more effectively. This article explains response time, typical values, influencing factors, and selection considerations.

Infrared thermometers measure surface temperature quickly without contacting the target. Depending on the model, their measurement range may extend from sub-zero temperatures to several hundred degrees Celsius, while specialized industrial instruments can measure much higher temperatures. This article explains typical temperature ranges, the main factors that determine measuring capability, and how to select an appropriate range.

The measurement range of a tachometer determines the lowest and highest rotational speeds the instrument can measure. This article explains RPM measurement range, the differences between contact and non-contact tachometers, how range differs from accuracy and resolution, and how to select a suitable tachometer for motors, fans, shafts, and rotating machinery.

RPM describes how many revolutions a rotating component completes per minute, while linear speed describes the distance traveled along a surface or moving material over time. By knowing the effective diameter or circumference of the rotating component, RPM can be converted into m/min, m/s, or other linear-speed units. This article explains the formulas, calculation steps, practical examples, and key factors that can affect accuracy.

Non-contact tachometers commonly use a reflective marker on the rotating surface. The reflective tape returns the emitted laser or measuring light to the photoelectric receiver, creating a periodic optical signal. By counting these pulses over time, the tachometer calculates rotational speed in RPM. Correct tape placement and proper optical contrast are essential for stable and reliable measurements.

A photoelectric tachometer is a non-contact instrument that measures rotational speed using optical sensing. It emits a light beam toward a rotating object, detects periodic reflections from a reflective marker, converts the optical signal into electrical pulses, and calculates rotational speed from the pulse frequency. This article explains the operating principle, key components, RPM calculation, and major factors affecting measurement accuracy.

Outdoor noise measurements can be affected by traffic variations, wind, building reflections, measurement distance, and background noise. Reliable results require more than simply reading a sound level meter. Proper instrument settings, representative measurement locations, suitable weather conditions, appropriate measurement duration, and complete field records are essential for obtaining accurate and comparable environmental noise data.

Measuring indoor noise involves more than reading a single decibel value. Measurement position, frequency weighting, time response, room occupancy, HVAC operation, doors and windows, and reflections from surrounding surfaces can all affect the result. This guide explains practical methods for measuring noise in homes, offices, classrooms, meeting rooms, and other indoor spaces, together with common measurement errors and key principles for interpreting the data.

Correct sound level measurement involves more than simply pointing the instrument at a sound source. Measurement range, A/C frequency weighting, FAST/SLOW time weighting, microphone position, environmental conditions, and calibration can all affect the result. This guide explains the recommended measurement procedure and key precautions for obtaining consistent and meaningful sound level data.

Sound level meters may gradually develop measurement deviations due to microphone sensitivity changes, environmental conditions, transportation, ageing, or mechanical shock. Field calibration checks with an acoustic calibrator and periodic laboratory calibration help confirm that the instrument continues to perform correctly. This article explains why sound level meters require calibration, how calibration is performed, and what users should consider in professional noise measurement applications.

MAX Hold is a common data-retention function on digital sound level meters. During measurement, the instrument continuously compares sound level readings and retains the highest value detected. It is particularly useful for machinery, production lines, construction sites, and other environments with fluctuating noise. However, a MAX Hold reading should not be confused with a true acoustic Peak measurement.

A digital sound level meter does more than display the current sound level in decibels. Depending on the model, it may also provide frequency weighting, time weighting, MAX/MIN, data hold, alarm, data logging, USB or Bluetooth communication. This article explains these common functions and the main differences between basic and data-logging sound level meters.