Table 2.

IoT sensor specifications and AWS Integration.

Parameter	Sensor model	Accuracy	Measurement range	Sampling frequency	AWS IoT protocol
Dissolved Oxygen	HACH LDO® Model 2	± 0.1 mg/L	0–20 mg/L	60 s	MQTT over TLS
pH	Mettler Toledo InPro	± 0.05 units	0–14 pH	60 s	MQTT over TLS
Temperature	PT100 RTD	± 0.1 °C	0–50 °C	60 s	MQTT over TLS
Ammonia (NH₃)	Orion™ ISE	± 2% full scale	0–1000 mg/L	300 s	MQTT over TLS
Nitrite/Nitrate	HACH NO₂/NO₃	± 2% full scale	0–100 mg/L	300 s	MQTT over TLS
Water Level	Ultrasonic HC-SR04	± 1 mm	20–4000 mm	300 s	MQTT over TLS
Flow Rate	Electromagnetic	± 0.5% reading	0–200 L/min	60 s	MQTT over TLS
Power Consumption	Digital Power Meter	± 1% reading	0–5000 W	300 s	MQTT over TLS