Chapter 9: Design Calculators — GW & DW Monitoring Design Guide

☀ Solar Power Sizing Calculator

Calculate the required solar panel wattage and battery capacity for a remote monitoring station. Inputs update results in real time as you drag the sliders.

RTU / Datalogger Power (W) Value: 5 W

Cellular Router Power (W) Value: 8 W

Sensors Total Power (W) Value: 10 W

Other Equipment (W) Value: 3 W

Daily Operating Hours (h/day) Value: 24 h/day

Peak Sun Hours (h/day) Value: 4.0 h/day

Battery Autonomy Days Value: 5 days

System Voltage (V)

📈 Sizing Results

— Daily Load (Wh/day)

— Recommended Panel (W)

— Battery Capacity (Ah)

Solar Margin —

Adjust inputs to see recommendations.

⚡ Sensor Cable Voltage Drop Calculator

Calculate voltage drop along sensor signal cables and verify that the sensor receives adequate supply voltage. Critical for 4-20 mA loops and RS485 power supply lines.

Cable Length (m) Value: 100 m

Wire Gauge (AWG)

Load Current (mA) Value: 20 mA

Supply Voltage (V) Value: 24 V

Min. Sensor Voltage (V) Value: 12 V

Temperature (°C) Value: 25 °C

📈 Voltage Drop Results

— Voltage Drop (V)

— Sensor Voltage (V)

— Drop % of Supply

Voltage Margin —

Adjust inputs to see recommendations.

💾 Data Storage & Bandwidth Estimator

Estimate local RTU storage requirements and cellular data consumption for a monitoring station. Helps size storage cards and select appropriate data plans.

Number of Parameters Value: 6 parameters

Sampling Interval (min)

Bytes per Record Value: 60 bytes

Transmission Interval (min)

Protocol Overhead (%) Value: 20%

Local Buffer Days Value: 30 days

📈 Storage & Bandwidth Results

— Daily Data (KB/day)

— Monthly Data (MB/mo)

— Buffer Storage (MB)

Monthly Data Breakdown

Adjust inputs to see recommendations.

🔔 Alarm Threshold & Hysteresis Calculator

Design alarm thresholds for water quality parameters using statistical baseline data. Calculates warning and alarm levels with hysteresis to minimize false alarms.

Parameter

Baseline Mean

Baseline Std Dev (σ)

Warning Level (× σ above mean) Value: 2.0× σ

Alarm Level (× σ above mean) Value: 3.0× σ

Hysteresis Band (%) Value: 10%

📈 Alarm Threshold Results

Level	Set Point	Reset Point	Action
Adjust inputs to calculate thresholds.

Adjust inputs to see recommendations.

📌 Water Quality Index (WQI) Scorer

Calculate a composite Water Quality Index score based on measured parameter values. The WQI provides a single number that summarizes overall water quality status for reporting and trend analysis.

pH (standard: 6.5–8.5) Value: 7.2

Turbidity (NTU, limit: 5) Value: 1.5 NTU

Residual Chlorine (mg/L, target: 0.2–1.0) Value: 0.50 mg/L

Conductivity (µS/cm, limit: 1500) Value: 400 µS/cm

Dissolved Oxygen (mg/L, min: 5) Value: 8.0 mg/L

Temperature (°C, limit: 25) Value: 18.0 °C

📈 Water Quality Index Results

—

WQI Score

—

Adjust parameter values to calculate WQI.