Articles (18)
Technology · 8 min read
Data logger vs RTU vs SCADA: what each one does
Three terms that tender documents use interchangeably, and the different jobs behind them: recording, reporting and controlling, and supervising.
Technology · 6 min read
4-20 mA, voltage or digital: sensor outputs compared
How a sensor hands its reading to a logger: current loop, voltage, SDI-12 or Modbus over RS-485, and what each choice means in the field.
Technology · 6 min read
Protecting field stations from heat, floods and vandalism
How to keep a river or weather station reporting through the hot season, the flood and the visitor with a spanner, by designing the site and the enclosure together.
Technology · 9 min read
Keeping stations reporting in floods: power and link backup
How a telemetry system loses power or signal at the worst moment, and the layered design that keeps flood data flowing.
Technology · 8 min read
Edge computing in field devices: local or cloud?
What edge computing in IoT means for a river station, what is better decided on the device, what belongs in the cloud, and a simple way to choose.
Product · 13 min read
How to install radar level and velocity sensors on a bridge
Where on the bridge to put them, how high and how far out to mount them, how to aim a velocity radar, and how to set and check the zero.
Technology · 7 min read
Warning siren testing and maintenance: a practical guide
How to run a warning siren test, from silent checks to full-volume and end-to-end tests, and the maintenance and records that keep a siren ready for the day it is needed.
Technology · 9 min read
Types of emergency sirens: mechanical, electronic and voice
How motor-driven, electronic and voice-capable warning sirens make their sound, what the standard warning signals mean, and how a flood siren is set off.
Technology · 11 min read
What is an automatic weather station (AWS)? How it works
The sensors on the mast, what the logger does with their signals every second and every ten minutes, and why an AWS record is not quite the same as a manual one.
Technology · 13 min read
How many automatic weather stations are there in India?
Who runs India's automatic weather stations and rain gauges, how many each operator reports, why published counts disagree, and where the data can be obtained.
Technology · 12 min read
Types of rain gauges used in India and how they work
The manual gauge read every morning, the siphon chart recorder, the tipping bucket behind automatic stations, weighing gauges and the newer optical and acoustic sensors: what each one measures and where it fits.
Technology · 12 min read
Accuracy, resolution, precision: reading a sensor datasheet
What the words and the ±x on a datasheet actually promise, why resolution is not accuracy, and how to put two sensors on the same footing before you choose one.
Technology · 12 min read
Batteries in the cold: chemistry for Himalayan winters
Why lead-acid and lithium iron phosphate batteries lose capacity in the cold, why charging lithium below freezing does lasting damage, and how to design a battery box that gets a remote station through a Ladakh January.
Technology · 13 min read
Sizing solar power for an off-grid monitoring station
A step-by-step method for the panel and battery of a remote river or weather station, worked through with real sunshine data for Mandi, including the monsoon minimum, losses, days of autonomy and shading by hills.
Technology · 11 min read
Modbus RTU explained: registers, function codes, pitfalls
How a Modbus RTU request and response are built byte by byte, what the four data tables and eight common function codes do, and the mistakes that most often turn a good sensor reading into a wrong number.
Technology · 13 min read
SDI-12 and RS-485: the two sensor buses hydromet stations rely on
How the two common wired sensor buses work, how far and how many they reach, how they compare with a 4–20 mA loop, and the wiring and addressing mistakes that cause most field faults.
Technology · 12 min read
Lightning and surge protection for remote field stations
How lightning gets into a solar-powered monitoring station, and how an air terminal, a single-point earth, surge protective devices and good cabling keep it working.
Solutions · 13 min read
Post-monsoon maintenance checklist for river monitoring stations
What to inspect, measure and record at a solar-powered river station once the monsoon has passed, and how to catch slow failures before the next one.