Comparison of Key Features of Weigh-In-Motion Sensors

The three mainstream types of Weigh-In-Motion (WIM) sensors：Quartz (Enviko and others), Plate Type, and Strip Strain Gauge, each have their own characteristics. Below is a comparative analysis of their features.

 

Quartz Piezoelectric sensors use the piezoelectric effect, offering high-frequency response, a wide measurement range, compact size, easy installation, and no power supply requirement. They work well for speeds from 1-200 km/h, have excellent long-term stability, low maintenance costs, and a lifespan of 5-10 years.

Plate Type sensors use strain resistance technology and are suitable for low-speed (0-40 km/h) or static weighing. Accuracy decreases above 30 km/h. Installation requires a large foundation pit, leading to long construction times, significant traffic disruption, high maintenance costs, and a short lifespan of 1-3 years.

Strip Strain Gauge sensors are designed for medium to low-speed weighing (1-60 km/h) but become less accurate above 40 km/h. Installation is complex, maintenance costs are high, and the lifespan ranges from 3-5 years.

Overall, Quartz Piezoelectric sensors perform best in terms of measurement range, long-term stability, easy installation, and low maintenance costs, making them ideal for high-speed WIM. Plate Type and Strip Strain Gauge sensors are more suitable for medium and low-speed applications.

Comparison of Key Features of Weigh-In-Motion Sensors
Category	Quartz		Plate Type	Strip Strain Gauge
	Enviko	Others
Technical Principle	Based on piezoelectric effect, charge output is proportional to force, high-frequency response, wide measurement range, small size, easy installation; no power supply required, excellent lightning protection performance.		Mechanical combined structure, resistance strain principle, sensor deformation under force, causing resistance change, suitable for low-speed or static weighing; requires power supply, poor lightning protection performance.	Resistance strain gauge sensor, mechanical deformation when sensor is subjected to force, reflecting the magnitude of force through deformation, suitable for quasi-static to low-frequency dynamic weighing; requires power supply, poor lightning protection performance.
Measurement Accuracy and Application	Suitable for medium, low, and high speeds (1-200km/h), fast response, almost unaffected by speed. Ideal for high-speed weigh-in-motion (WIM), can also be used for traffic flow surveys and vehicle type classification.		Suitable for low speed (0-40km/h), accuracy decreases when speed exceeds 30km/h.	Suitable for medium and low speeds (1-60km/h), unstable accuracy when speed exceeds 40km/h.
Long-Term Stability	Resistant to high and low temperatures and humidity changes, suitable for complex environments. Stable, no frequent calibration required.		Susceptible to drift, requires regular calibration.	Susceptible to drift, requires regular calibration.
Installation Method	Simple and fast installation, only need to cut a small 50mm*70mm slot, minimal slotting, short construction period, minimal impact on traffic.		Requires digging a 1200mm*800mm foundation pit, significant damage to the road, long construction period, significant impact on traffic. Also need to consider drainage.	Need to cut a  100mm*100mm slot, more complex construction.
Maintenance Cost	Low, stable, no frequent maintenance required for long-term use.		High (requires regular calibration, prone to deformation and corrosion, high maintenance cost).	High (requires regular calibration, prone to deformation and corrosion, high maintenance cost).
Service Life	5 years. Generally 5 to 7 years, may be shorter in extreme cases (e.g., areas using studded tires), may exceed 10 years in areas with good road conditions.		1-3 years (prone to deformation fatigue).	3-5 years (prone to deformation fatigue).
Driving Experience and Traffic Safety	No impact. Good for safety		Significant physical sensation; large surface area of steel plate, prone to vehicle sideslip in rain and snow.	No impact. Good for safety
Cost	Cheaper overall installation. Reasonable  sensors price, high cost-effectiveness	Cheaper overall installation. Expensive sensors( poor cost-effectiveness),	Cheaper sensors themselves, more expensive overall installation.	Medium cost.
Consistency Between Sensors	Each sensor's sensitivity parameter (pC/N) is controlled within the range of -1.8 to -2.1, demonstrating better consistency in precision.	Each sensor's sensitivity parameter (pC/N) is controlled within the range of 1.7 (±12%), showing excessive fluctuation and poorer consistency in precision.	▁	▁
Sensor signal polarity	Both positive and negative signals are supported. Polarity can be customized based on customer requirements for greater adaptability.	Negative signal	▁	▁

By Max Chung

max@enviko-tech.com