What is the difference between brass and plastic water meters?

Brass meters offer higher impact resistance, excellent aging resistance (over 20 years lifespan vs 5-10 years for plastic), more stable measurement accuracy over time, and more reliable sealing. Plastic meters are more cost-effective but may experience oxidation, hardening, or embrittlement long-term, especially in high-temperature or direct sunlight environments.

Does a prepaid meter have to come with a SIM card?

No. The basic technology used in prepaid meters is STS (Standard Transfer Specification), a secure message system that does not require internet. The sales point encrypts credit information to generate a 20-digit token, which the user enters via the meter keypad to recharge. A SIM card is only needed for remote meter reading or remote management functions.

What is an STS prepaid electricity meter?

An STS prepaid electricity meter is a meter that uses the Standard Transfer Specification to accept secure 20-digit recharge tokens. It is commonly used by utilities, landlords, and property operators that need token-based credit control without requiring every meter to stay online.

When should a project use a three-phase prepaid electricity meter?

A three-phase prepaid electricity meter is normally used for three-phase commercial, industrial, or utility service connections. The buyer should confirm the nominal voltage, maximum current or CT ratio, installation method, accuracy requirement, communication coverage, and destination-market standards before selecting a model.

What is the difference between the CA368 GPRS and standalone STS models?

Both CA368 models support STS 20-digit token prepayment for three-phase service connections. The CA368 GPRS model adds direct cellular communication for remote reading, monitoring, and meter management. The standalone CA368 STS model uses keypad token entry without requiring always-on remote communication, which is suitable when secure prepayment is needed but direct cellular management is not.

What information is needed for a CA368 three-phase meter quotation?

Provide the nominal voltage, maximum current or CT ratio, installation and wiring requirement, GPRS or standalone communication preference, vending or API requirement, estimated quantity, target deployment conditions, and required destination-country standards or utility specifications.

Which prepaid meter is suitable for Africa utility projects?

For many Africa utility and sub-metering projects, CalinMeters recommends STS prepaid electricity meters because 20-digit token recharge can work without continuous network coverage. Split keypad meters and CIUs are useful when the meter is installed outdoors, locked in a cabinet, or mounted on a pole. GPRS, DCU, or LoRaWAN options can be added when remote reading or AMI management is required.

What information should a utility provide when requesting prepaid meters for Africa?

The utility should provide the service type and maximum current, single-phase or three-phase requirement, installation method, built-in or split keypad preference, STS vending and payment workflow, remote communication requirement, destination-country standards or type approvals, estimated quantity, and pilot conditions. These details allow Shenzhen Calinmeter Co., Ltd. to match the meter, CIU, communication device, and vending integration to the project.

What compliance information is needed for an Africa prepaid meter project?

Compliance requirements differ by country and utility. Before selecting a model, the buyer should identify the required national standards, utility specifications, type approvals, accuracy class, enclosure rating, test reports, and documentation. CalinMeters can then confirm which requirements and documents apply to the proposed meter configuration without making assumptions about the destination market.

Which meter types are suitable for Southeast Asia smart metering projects?

For Southeast Asia projects, CalinMeters usually selects the meter according to building density, communication coverage, and utility workflow. LoRaWAN smart water meters are useful for communities and municipal service areas with many meters in one area. STS prepaid electricity meters are practical for token-based credit control, and prepaid gas meters with LoRaWAN are suitable where valve control and remote reading are required.

How should a utility choose a prepaid gas meter?

Choose a prepaid gas meter only after confirming the gas service, meter size and flow requirement, installation environment, valve operation, customer recharge method, remote reading requirement, and destination-market standards. The CA768 combines STS token prepayment with LoRaWAN communication, but the final configuration should be checked against the local utility specification and a representative pilot.

Why use LoRaWAN for a prepaid gas meter project?

LoRaWAN is useful when many gas meters are installed in one service area and the operator needs remote reading without a cellular subscription in every meter. Practical coverage depends on building materials, meter location, gateway placement, terrain, and local radio conditions, so the network should be validated with a site survey and pilot.

What information is needed for a prepaid gas meter quotation?

Provide the gas type and service conditions, required meter size and flow range, installation orientation and environment, valve and STS prepayment requirements, keypad or customer interface requirement, LoRaWAN network and gateway plan, estimated quantity, destination country, required utility specifications or approvals, and pilot acceptance conditions.

What is the expected battery lifetime for Calin meters?

For both ultrasonic and multi-jet meters, the expected battery lifetime is 5-10 years. Our ultrasonic meters contain double the battery capacity of multi-jet models. The actual lifespan depends heavily on usage patterns — frequent valve operations (opening/closing) consume more battery. Battery replacement is simple for both meter types when needed.

What is the difference between LoRa and LoRaWAN?

LoRaWAN is an enhanced and optimized version of LoRa technology. Key differences: LoRaWAN has better connectivity and penetration (1-1.5 km vs LoRa less than 1 km), real-time data granularity (hourly vs 24-hour latency), and can manage over 500 meters per gateway versus 200-300 for LoRa.

What causes signal noise in PLC communication?

PLC (Power Line Communication) signal noise can be caused by: electromagnetic interference from motors and switching power supplies, design flaws like impedance mismatch or aging infrastructure leading to signal reflection, interference from other frequency bands, and inherent environmental noise. LoRaWAN is recommended as an alternative as it operates in a cleaner electromagnetic environment with frequency-hopping capabilities that automatically switch channels to maintain stable connectivity.

How many meters can be managed by one gateway?

We recommend managing up to 500 meters per LoRaWAN gateway. The communication distance between gateway and meters is up to 2 kilometers by line of sight.

When should a utility choose LoRaWAN instead of GPRS for smart meters?

LoRaWAN is often preferred when a project has many meters in one service area and wants lower communication operating cost without a SIM card in every meter. GPRS is useful when cellular coverage is available and each meter needs direct wide-area connectivity.

Which CalinMeters water meter is best for a LoRaWAN AMI project?

For LoRaWAN AMI water projects, plastic multi-jet meters are usually chosen for cost-sensitive residential rollouts, brass multi-jet meters are better for tougher installation environments, and ultrasonic water meters are preferred when long-term measurement stability and no moving parts are more important than the lowest upfront cost.

What is the difference between multi-jet and ultrasonic prepaid water meters?

A multi-jet water meter uses a mechanical measuring mechanism and is often selected for familiar operation and lower initial cost. Plastic-body models suit cost-sensitive standard installations, while brass-body models provide a stronger metal enclosure. An ultrasonic meter has no moving measuring parts and is selected when long-term measurement stability is more important than the lowest initial cost. All project choices should be confirmed against flow range, water quality, installation conditions, communication, battery, and destination-market requirements.

What information is needed for a LoRaWAN smart water meter quotation?

Provide the pipe size, expected flow range, water quality and temperature, installation orientation, plastic or brass body preference, multi-jet or ultrasonic preference, valve and STS prepayment requirement, keypad or CIU requirement, communication method, estimated meter density, gateway or backhaul plan, quantity, and required destination-country standards or utility specifications.

How should a utility plan LoRaWAN coverage for smart water meters?

Start with a site survey and pilot rather than relying only on a quoted maximum distance. Building materials, terrain, meter boxes, installation height, underground locations, local interference, gateway placement, and backhaul availability all affect practical coverage. Test representative meter locations before fixing the gateway quantity and rollout plan.

How is the gateway powered?

The gateway is powered by grid power, not by battery.

How does a token based prepaid meter work?

A token based prepaid meter uses STS security to load credit before consumption. The operator registers the meter in a vending system, the customer buys credit, the system generates a secure 20-digit token, and the customer enters that token on the meter keypad or CIU. Remote recharge can also be supported when the project uses GPRS, LoRaWAN, or AMI integration.

When should a utility choose a split keypad prepaid meter?

A split keypad prepaid meter is useful when the main meter is installed outdoors, locked in a cabinet, mounted on a pole, or placed where the customer should not access the wiring compartment. The CIU gives the customer an indoor keypad for token entry, balance checking, and consumption information while the main meter remains protected.

Do prepaid meter tokens have an expiry date?

Tokens for prepaid meters do not have an expiry date. They remain valid indefinitely. However, if a user enters 50 new tokens after losing one, the lost token would no longer work. This scenario is rare, as most users contact their service provider to reprint lost tokens.

How does the vending system work?

Our vending system is a web browser-based platform. You log in, select the meter number, and generate tokens. The system is flexible and compatible with third-party payment gateways like mobile money. When a customer purchases a token, it can be automatically sent remotely to the meter, so the customer does not need to enter the token manually.

Do you provide the management system or can we use our own?

We are manufacturers focused on meters and solutions. Most of our clients have their own software. We provide API to allow partners to build their own platform. Alternatively, we also offer our own vending system if needed.

Can CalinMeters integrate with a third-party payment or vending platform?

Yes. Shenzhen Calinmeter Co., Ltd. can support API integration for partners that already operate payment, vending, or meter management software. This is useful for utilities and system integrators that want to keep their existing customer platform while adding STS prepaid meters, CIUs, DCUs, LoRaWAN gateways, or AMI devices.

Can STS prepaid meters work with mobile money in Africa?

Yes, when the vending and payment integration is configured for the project. A customer can pay through a mobile money channel, the payment platform can request an STS token through the vending system or API, and the token can be delivered to the customer for keypad or CIU entry. Remote token delivery may also be available when the selected meter and communication architecture support it.

What are your payment terms?

We usually take a deposit as advance payment, then manufacture, and before shipment we collect the balance. For large quantity orders, we offer batch-by-batch rolling payment terms — you can divide large orders into batches, pay per batch as you withdraw, and we maintain reserve stock for continuous supply.

What is your warranty policy?

Meters are free from defects in material and workmanship for 18 months from the date of confirmed receipt. We ship 0.2% of the main order as free replacements. Before warranty expiry, after the provided free replacements are consumed, Calin will continue to provide free replacements for any confirmed defective meters due to quality issues.

Can you share the price list?

Please contact us directly at Scott@szcalinmeter.com or via WhatsApp/WeChat at +8613713788753 and we will send a quote as soon as possible.

What is a CIU (Customer Interface Unit)?

A CIU is an extension keypad for the meter, especially for meters without a built-in keypad like DIN rail meters. These meters are usually locked and mounted on poles for better communication with the gateway and for theft prevention. The CIU allows users to conveniently enter tokens and check balances.

What is a DCU (Data Concentrator Unit)?

A DCU is not a meter but a separate data device that acts as a gateway between meters and the back-end system. DCUs are used for cluster installations — for example, in a village with many households. Using a DCU is more cost-effective than putting a SIM card in each meter, as meters with SIM cards are more costly than those without.

What equipment is needed for an AMI metering solution?

A typical AMI metering solution includes smart prepaid meters, CIUs when users need a separate keypad or display, DCUs or LoRaWAN gateways for data collection, and a back-end vending or meter management platform for token, reading, and device operations.

Can ultrasonic meters work without a CIU?

Yes, our ultrasonic meters can operate without a CIU as they have an integrated keypad. However, we recommend CIUs when meters are installed outdoors or enclosed in anti-tamper boxes, as the CIU significantly enhances accessibility and functionality in these scenarios.

How mature is the ultrasonic water meter technology?

After implementing improvements to address initial field issues, our ultrasonic meters (with over 1,000 units deployed) have operated successfully for more than a year without customer complaints. They share similar electronic components with our mature multi-jet meters but feature simpler mechanical structures. We recommend conducting pilot tests before large-scale deployment.

Smart Prepaid Metering Solutions

Electricity · Water · Gas

Product portfolio

Smart Metering Products

Explore prepaid energy, water and gas meters, plus AMI devices for data collection and network connectivity.

Utility buyer guide

How to select prepaid meters by project market

These answers help utility buyers compare STS prepaid electricity meters, LoRaWAN smart water meters, prepaid gas meters, and AMI components before requesting specifications.

Prepaid meter for Africa

STS prepaid electricity meters, keypad water meters, CIU, and AMI devices

For African utility and sub-metering projects, CalinMeters usually recommends STS prepaid meters because 20-digit token recharge can work even where network coverage is inconsistent.

Use keypad STS electricity meters for basic prepaid rollout and token-based credit control.
Use split keypad or CIU configurations when meters are locked outdoors, mounted on poles, or installed in anti-tamper boxes.
Add GPRS, DCU, or LoRaWAN devices when the project also needs remote reading and AMI management.

Prepaid meter for Southeast Asia

LoRaWAN smart water meters, prepaid electricity meters, and prepaid gas meters

For Southeast Asia, CalinMeters usually matches the meter to building density, network availability, and utility operations: LoRaWAN is useful for clustered water meter reading, while STS prepaid electricity meters remain practical for token sales.

Use LoRaWAN smart water meters where many meters are installed in communities, compounds, or municipal service areas.
Use ultrasonic water meters when no moving parts and long-term measurement stability are more important than lowest upfront cost.
Use prepaid gas meters with LoRaWAN when operators need valve control, credit management, and remote reading.

Smart metering solution for utilities

AMI solution with meters, CIUs, DCUs, LoRaWAN gateways, and vending software

A smart metering solution for utilities should be planned as a system, not only as individual meters. Shenzhen Calinmeter Co., Ltd. combines STS prepaid meters, CIUs, DCUs, LoRaWAN gateways, and API-ready vending support for utility projects.

Use CIUs when customers need indoor token entry and balance checking.
Use DCUs or LoRaWAN gateways when many meters should report through shared network equipment.
Use API integration when the utility or partner already has payment, vending, or meter management software.

STS token workflow

How a token based prepaid meter works

A token based prepaid meter uses STS security to load credit before consumption. The same workflow can support standalone keypad meters, split keypad prepaid meters with a CIU, and AMI projects with remote management.

1. Register meter

The utility or operator registers the STS prepaid meter number in a vending or meter management system.

2. Sell credit

The customer buys electricity, water or gas credit through a sales point, mobile money channel or integrated payment system.

3. Generate token

The vending system encrypts the credit into a secure 20-digit STS token linked to that meter.

4. Recharge meter

The customer enters the token on the meter keypad or CIU. Remote recharge can be added when the project uses GPRS, LoRaWAN or AMI integration.

Choose a built-in keypad meter when the customer can access the meter directly.

Choose a split keypad prepaid meter or CIU when the meter is locked outdoors or mounted on a pole.

Choose API-ready vending support when the utility already has payment or customer management software.

Selected category

Energy Meter

STS prepaid electricity meters for residential and commercial use

Browse focused product groups below. Download links are available on products with published specifications.

Selection guide

How to choose an STS prepaid electricity meter

For utility and property projects, choose the meter by installation type, phase requirement and remote management needs. A keypad STS prepaid meter can work with 20-digit tokens without a network connection, while GPRS or LoRaWAN models support remote reading and AMI management.

Single phase meters fit residential users and small commercial loads.

Three phase and CT meters fit higher-current commercial or industrial sites.

DIN rail meters are often paired with a CIU when the meter is locked outdoors or mounted on a pole.

Three phase buyer guide

CA368 GPRS or standalone STS: which model fits the project?

Both CA368 models support STS prepaid electricity metering for three-phase service connections. The main selection decision is whether the project needs direct GPRS communication or only secure keypad token operation.

Model	Communication	Best fit	Token operation
CA368 Smart STS Prepaid Three Phase Energy Meter (GPRS)	GPRS	Utilities and commercial projects that need direct remote reading, monitoring, and meter management.	STS 20-digit token entry remains available while GPRS adds remote data and management functions.
CA368 STS Prepaid Three Phase Energy Meter	Standalone STS	Commercial or utility connections that need secure token prepayment without always-on remote communication.	Customers enter 20-digit STS tokens directly on the meter keypad.

Before requesting a quotation, provide the nominal voltage, maximum current or CT ratio, installation method, communication coverage, vending or API requirement, estimated quantity, and destination-market standards or utility specifications.

Single Phase Energy Meter

STSLoRaWANDIN Rail

CA168 Smart STS Prepaid DIN Rail Energy Meter (LoRaWAN)

DIN rail STS prepaid energy meter with LoRaWAN communication for remote meter reading and token management.

Specification (PDF)

STSGPRSPrepaid

CA168 Smart STS Prepaid Energy Meter (GPRS)

STS prepaid single-phase meter with GPRS communication for remote monitoring and control.

Specification (PDF)

STSPrepaid

CA168 STS Prepaid Energy Meter

Standard STS prepaid single-phase energy meter with keypad for token entry.

Three Phase Energy Meter

STSGPRSPrepaid

CA368 Smart STS Prepaid Three Phase Energy Meter (GPRS)

Three-phase STS prepaid electricity meter for commercial, industrial, and utility service connections, with GPRS communication for remote reading and management.

Specification (PDF)

STSPrepaid

CA368 STS Prepaid Three Phase Energy Meter

Standalone three-phase STS prepaid electricity meter with keypad token entry for projects that do not require always-on remote communication.

Specification (PDF)

CT Meter

CT Operated Energy Meter

Transformer-operated (CT) energy meter for high-current commercial and industrial metering.

Metering solutions

Solutions for utility metering projects

Use these project scenarios to match prepaid meters, communication devices, and AMI components before requesting a quote.

Electricity utilities and property operators

STS prepaid electricity meter projects

CalinMeters STS prepaid electricity meters help utilities, landlords, and sub-metering operators collect payment before consumption while still supporting familiar 20-digit token workflows.

Single phase, three phase, DIN rail, and CT options cover residential, commercial, and high-current installations.
Keypad STS meters can operate without a live network connection for basic token recharge.
GPRS and LoRaWAN models support remote reading, remote monitoring, and AMI project management.

STS prepaid electricity metertoken based prepaid metersplit keypad prepaid meter

Water utilities and residential communities

LoRaWAN smart water meter deployments

LoRaWAN smart water meters are suitable for projects that need remote reading without placing a SIM card in every meter. Multi-jet and ultrasonic options support different budget, durability, and accuracy requirements.

Plastic multi-jet meters are practical for cost-sensitive residential rollouts.
Brass multi-jet meters are better for tougher installation environments.
Ultrasonic meters have no moving parts and are useful when long-term measurement stability matters.

LoRaWAN smart water meterprepaid water meterultrasonic water meter

Remote reading and data collection

AMI metering solution architecture

An AMI metering solution typically combines smart meters, CIUs, DCUs or LoRaWAN gateways, and a back-end vending or meter management platform for token, reading, and device operations.

CIUs keep token entry and balance checks accessible when meters are locked outdoors or mounted on poles.
DCUs aggregate meter data for dense clusters such as villages, compounds, and utility service areas.
LoRaWAN gateways connect smart meters to the network where remote reading is required at scale.

AMI metering solutiondata concentrator unitLoRaWAN gateway

Residential and commercial gas metering

Prepaid gas meter applications

CalinMeters prepaid gas meters combine STS token security, valve control, and LoRaWAN communication for projects that need credit control and remote reading in gas applications.

STS prepayment supports secure token-based credit management.
LoRaWAN communication reduces dependence on individual cellular subscriptions.
Remote reading helps operators monitor consumption and reduce manual field collection.

prepaid gas meterSTS gas metersmart gas meter

LoRaWAN water meter selection

Plastic, brass, or ultrasonic: which smart water meter fits the project?

Shenzhen Calinmeter Co., Ltd. supplies STS prepaid water meters for utility and community projects. Select the meter by measurement principle, body material, field conditions, communication coverage, lifecycle expectations, and destination-market requirements.

Meter type	Measurement principle	Communication	Best fit	Confirm before quotation
Plastic multi-jet prepaid water meter	Mechanical multi-jet	LoRaWAN	Cost-sensitive residential and community rollouts with standard installation conditions.	Confirm pipe size, flow range, water quality, installation orientation, valve requirement, and enclosure conditions.
Brass multi-jet prepaid water meter	Mechanical multi-jet	LoRaWAN	Projects that prefer a stronger metal body for tougher installation environments.	Confirm pipe size, flow range, water quality, body-material requirement, valve operation, and local compliance documents.
Ultrasonic prepaid water meter	Ultrasonic, no moving measuring parts	LoRaWAN or GPRS	Projects that prioritize no moving measuring parts and long-term measurement stability over the lowest initial cost.	Confirm flow range, installation conditions, keypad or CIU access, communication coverage, battery expectations, and pilot requirements.

For LoRaWAN projects, complete a site survey before rollout. Gateway placement, building materials, terrain, meter-box location, and local radio conditions affect practical coverage, so a pilot is more reliable than choosing equipment from a distance figure alone.

Request water meter configuration

Prepaid gas meter selection

What should a utility specify before buying a prepaid gas meter?

Shenzhen Calinmeter Co., Ltd. supplies the CA768 smart STS prepaid gas meter with LoRaWAN communication. A utility or system integrator should define the gas service, valve workflow, customer recharge method, network design, and destination-market requirements before requesting a final configuration.

Gas service and meter sizing: Define the gas type, service pressure, required meter size, expected flow range, installation orientation, and environmental conditions before selecting a configuration.
Prepayment and valve operation: Confirm the STS token workflow, credit rules, valve close and reopen process, emergency-credit policy, and the customer support procedure for failed recharge or valve events.
Customer recharge access: Specify how customers will receive and enter 20-digit STS tokens and whether the installation needs a separate customer interface for convenient indoor access.
LoRaWAN network design: Document meter density, building materials, meter location, gateway placement, backhaul, and expected reporting interval. Validate representative locations with a site survey and pilot.
Compliance and pilot acceptance: Identify destination-country standards, utility specifications, required approvals, test documents, installation rules, and pilot acceptance criteria before final model confirmation.

Do not select a gas meter from communication technology alone. Meter sizing, local installation rules, valve behavior, required approvals, and the operating procedure for customers and field teams must be confirmed together. A representative pilot should test token recharge, valve operation, radio coverage, and back-end data before mass rollout.

Request gas meter configuration

Africa utility procurement

What to specify before buying prepaid meters for Africa

Utilities and system integrators should define the electrical service, installation method, STS vending workflow, communication architecture, destination-market compliance, and pilot plan before requesting a final meter configuration.

Load and meter type: Specify single phase, three phase, DIN rail, or CT-operated metering according to the service connection and maximum current.
Installation and customer access: Choose a built-in keypad when the meter is accessible. Choose a split keypad prepaid meter or CIU when the meter is locked outdoors, mounted on a pole, or installed in an anti-tamper enclosure.
STS vending and payment: Confirm 20-digit STS token vending, sales-point workflow, mobile money integration, and whether an API is needed for an existing payment or customer platform.
Communication and AMI: Use standalone token meters for basic prepayment. Add GPRS, LoRaWAN, a DCU, or a gateway when remote reading, alarms, or device management are required.
Destination-market compliance: State the required national standards, utility specifications, type approvals, accuracy class, enclosure rating, and documentation before model selection. Requirements differ by country and project.
Pilot and rollout plan: Run a pilot with representative installation conditions, test token and payment workflows, verify communication coverage, and confirm field procedures before mass deployment.

Request project configuration

Why Choose Calin Meters?

Trusted by customers worldwide

High Precision

Accurate measurement with advanced metering technology

Secure Prepaid

STS certified prepaid technology for secure token management

IoT Enabled

NB-IoT, LoRaWAN, GPRS communication for remote monitoring

Certified Quality

International standards and multiple product certifications

About Calin Meters

We are a professional manufacturer specializing in the design and production of smart prepaid meters for electricity, water, and gas.

With years of experience in the industry, we provide comprehensive metering solutions including integrated energy remote meter reading systems and big data management analysis platforms.

15+

Years Experience

50+

Countries Served

Frequently Asked Questions

Expert answers to common questions about our products

Latest News

Industry insights and company updates

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The Dual-Track Evolution of Gas Meters

Diaphragm and ultrasonic gas meters are complementary symbiotic in dual-track evolution.

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IoT Technology

March 12, 2026

Introduction to IoT Protocols

Understanding MQTT, CoAP, Modbus, and other communication protocols.

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Water Metering

March 10, 2026

Mechanical Water Meters Introduction

Affordable, reliable, and widely used worldwide.

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Phone

+8613713788753

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Email

scott@szcalinmeter.com

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