Chart Recorders in Industrial Automation

temperature pressure flow level humidity ph conductivity

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In this article, we break down what Honeywell chart recorders are, how paper and paperless recorders differ, where they're used, and why many facilities still rely on them—even with modern PLCs, SCADA systems, and historians.

[industrial automation / Chart Recorder]

What Does a Chart Recorder Do?

A chart recorder:

Receives signals from sensors, transmitters, controllers, or PLCs
Displays the current value
Records the value over time
Stores data for troubleshooting, compliance, quality control, and historical analysis
Generates alarms when values exceed limits
Provides evidence that a process stayed within required parameters

Process	Variable Recorded
Boiler Plant	Steam pressure, water temperature
Chiller Plant	Supply/return temperatures, differential pressure
Pharmaceutical Manufacturing	Batch temperatures
Food Processing	Pasteurization temperatures
Water Treatment	pH, chlorine levels, flow rates
Chemical Plant	Reactor temperature and pressure

[industrial automation / Traditional Chart Recorder]

How They Work?

Paper chart recorders use a motor-driven chart and pens. The result is a continuous trace showing process conditions over time.

The recorder:

Receives an analog signal (typically 4-20mA)
Converts it to a measured value
Moves a pen across chart paper
Rotates the chart at a predetermined speed

Circular Chart Recorder

The chart rotates like a clock

Common chart durations:
24 hour
7 day
31 day

Typical applications:
Boiler rooms
Water treatment plants
Compressed air systems
Refrigeration systems

Strip Chart Recorder

Instead of a rotating chart, paper continuously feeds through the recorder.

Advantages:
Longer recording periods
Higher resolution
Multiple channels

Common uses:
Laboratory testing
Environmental monitoring
Process troubleshooting

[industrial automation / Why popular]

Why Paper Recorders Were Popular

Regulatory Compliance
Many industries required a physical, permanent record.

Examples:

FDA pharmaceutical facilities
Food processing plants
Power plants
Hospitals

Simple Operation
Even during a computer failure:

The paper keeps moving
The pen keeps writing
Operators can immediately see process trends

Technicians could walk up to the recorder and instantly see:

When a process drifted
How long an alarm condition lasted
Whether a control loop was stable

[industrial automation /Common

Common Honeywell Paper Recorder Families

Some Honeywell models commonly encountered in the field include:

Honeywell DR4300
Honeywell DR4500
Honeywell DPR250 (early hybrid systems)
Honeywell Minitrend

Many older facilities still have DR4300 recorders operating today.

[industrial automation /Paperless

Paperless Recorders

As PLCs, SCADA systems, and industrial networks became common, paper recorders evolved into digital recorders.

Instead of a pen writing on paper:

Data is stored electronically
Trends appear on a color display
Historical data is saved internally
Data can be exported to USB drives or servers

How Paperless Recorders Work

Typical architecture:
Sensor

Transmitter

Paperless Recorder

Display

Internal Memory

Ethernet / SCADA / Historian

The recorder continuously stores:

Time stamps
Process values
Alarm events
Operator actions
Audit trails

Common Features

Multi-Channel Recording
Modern units commonly support:

6 channels
12 channels
18 channels
24 channels
48 channels

Examples of recorded signals:

Thermocouples
RTDs
4-20mA transmitters
Voltage signals
Pulse inputs

Data Storage

Instead of paper charts:

Internal flash memory
SD cards
USB drives
Network servers

Storage often covers months or years.

Alarm Management

Recorders can:

Annunciate alarms
Trigger relays
Send emails
Log alarm history

Useful for:

Critical temperatures
High pressure events
Chiller failures
Boiler trips

Electronic Signatures

Industries such as pharmaceuticals often require:

User logins
Audit trails
Electronic signatures

This helps comply with regulations like:

FDA 21 CFR Part 11

Honeywell Paperless Recorder Families

Honeywell Minitrend GR

Features:

Color touchscreen
Multiple analog inputs
USB export
Ethernet communications

Common in:

Water treatment
Chemical processing
Food manufacturing

Honeywell Multitrend GR

Features:

Larger display
More channels
Audit trails
Batch recording

Common in:

Pharmaceutical plants
Refineries
Power generation

Honeywell eZtrend

Features:

Lower cost
Compact footprint
Small systems

Common in:

OEM equipment
Small process systems
Pilot plants

Recorder vs PLC Historian vs SCADA Historian

Many new technicians ask why a recorder is needed if a PLC or SCADA system already stores data. This independence is why recorders remain common in regulated industries.

Feature	Recorder	PLC	SCADA Historian
Independent of control system	Yes	No	No
Regulatory acceptance	High	Moderate	High
Local display	Yes	Limited	Usually remote
Easy validation	Yes	More difficult	More difficult
Dedicated archive	Yes	Limited	Yes
Continues if SCADA fails	Often	Sometimes	No