HM Digital ORP-200 Professional Waterproof ORP Meter | Digital ORP & Temperature Tester

Product Name

HM Digital ORP-200 Professional Waterproof ORP/Temperature Meter | Oxidation Reduction Potential Tester | -999 to +1000 mV | 1 mV Resolution | Replaceable Sensor

Brand

HM Digital

Model

ORP-200

Product Category

Water Quality Testing Instruments → ORP Meters / Redox Meters

Product Type

Digital Handheld ORP & Temperature Meter

Short Product Description

The HM Digital ORP-200 is a professional handheld digital ORP meter designed to measure Oxidation Reduction Potential (ORP/Redox) and temperature in liquids. It provides an ORP measurement range of -999 to +1000 mV, with 1 mV resolution and accuracy of 0.5% (±2 mV).

The meter features a waterproof, submersible housing, digital calibration, data-hold functionality, automatic shut-off and a replaceable sensor, making it suitable for laboratory, field and water-treatment applications.

Detailed Product Overview

The HM Digital ORP-200 is designed for users who need quick and reliable measurement of oxidation-reduction potential in water and other compatible liquids.

ORP, also known as Redox Potential, indicates the tendency of a liquid to gain or lose electrons. ORP measurements are commonly used to monitor oxidation processes, disinfectant effectiveness and water-treatment conditions.

The ORP-200 combines ORP measurement with temperature measurement in a compact handheld design. Its waterproof housing allows the meter to be submerged during testing, while the replaceable sensor helps extend the useful life of the instrument.

The meter is factory calibrated and provides digital calibration with fine adjustment, allowing users to maintain measurement accuracy during regular use.

Key Features

• Measures Oxidation Reduction Potential (ORP/Redox)

• Measures liquid temperature

• ORP range: -999 to +1000 mV

• ORP resolution: 1 mV

• Accuracy: 0.5% (±2 mV)

• Temperature resolution: 0.1°C / 0.1°F

• Waterproof, submersible housing

• IP-67 waterproof protection according to current product references

• Replaceable sensor

• Digital push-button calibration

• Auto-ranging calibration with digital fine-tuning

• Data-hold function

• Low-battery indicator

• Automatic shut-off after approximately 5 minutes

• Large, easy-to-read LCD display

• Compact handheld design

• Floats when submerged

• Includes batteries and lanyard

• Suitable for field and laboratory applications

Technical Specifications

Note: HM Digital documentation contains specifications from different production revisions. In particular, battery configuration and some temperature specifications vary between older and newer references. For the current physical stock, the manufacturer's supplied packaging/manual should take precedence.

What Does ORP Measure?

ORP stands for Oxidation Reduction Potential.

ORP measures the ability of a liquid to oxidize or reduce substances. It is expressed in millivolts (mV).

Generally:

• Higher positive ORP → greater oxidizing potential

• Lower ORP → lower oxidizing potential or greater reducing conditions

• ORP can be useful for monitoring oxidation and disinfection processes

ORP measurement is particularly useful where water sanitation and oxidation processes need to be monitored.

Applications

The HM Digital ORP-200 can be used for a wide range of applications, including:

Water Treatment

• Drinking water testing

• Water purification

• Water treatment plants

• STP and ETP applications

• Disinfection monitoring

Swimming Pools & Spas

• Pool water monitoring

• Sanitizer effectiveness monitoring

• Spa water testing

Aquaculture & Aquariums

• Aquarium water monitoring

• Aquaculture systems

• Fish farming

• Water quality monitoring

Hydroponics & Agriculture

• Hydroponic systems

• Agricultural water testing

• Irrigation water monitoring

Environmental Testing

• Environmental water testing

• Field water-quality measurements

• Wastewater monitoring

Industrial Applications

• Cooling tower monitoring

• Ozone system monitoring

• Metal finishing

• Process-water monitoring

Laboratory & Research

• General laboratory ORP testing

• Chemical process monitoring

• Research applications

HM Digital lists applications including water purification, agriculture, aquariums/aquaculture, chlorine monitoring, environmental testing, hydroponics, pharmaceutical/medical applications, pools/spas and water treatment.

Major Advantages

Waterproof Design

The ORP-200 has a waterproof, submersible housing, making it suitable for direct testing in water samples and field environments.

Replaceable Sensor

The sensor can be replaced without replacing the complete meter, helping reduce long-term operating costs.

High Resolution

With 1 mV ORP resolution, the meter allows users to monitor relatively small changes in ORP levels.

Digital Calibration

The instrument uses digital calibration with fine adjustment, making calibration straightforward.

Portable

Its compact handheld form factor makes it convenient for laboratories, water-treatment facilities and on-site testing.

Temperature Measurement

The meter simultaneously provides temperature information along with ORP measurements.

Data Hold

The data-hold function allows users to freeze the displayed measurement for easier recording.

Calibration

The ORP-200 uses auto-ranging calibration with digital fine tuning.

The instrument is factory calibrated, but ORP meters should be recalibrated periodically depending on usage and required accuracy.

For best measurement performance:

1. Use an appropriate ORP calibration solution.

2. Clean/rinse the sensor before calibration.

3. Place the sensor into the calibration solution.

4. Allow the reading to stabilize.

5. Perform the digital calibration adjustment.

6. Rinse the sensor after calibration.

7. Store the sensor appropriately.

HM Digital recommends regular recalibration because ORP electrode performance can change with use.

Sensor Information

Sensor Type: Replaceable electrode
Sensor Model: SP-O2
Construction: Glass sensor and reference electrode assembly

A replaceable sensor allows the ORP-200 to remain useful even after the original electrode reaches the end of its service life.

Important Usage Information

For accurate and stable ORP measurements, the liquid being tested needs sufficient conductivity. HM Digital documentation states that the meter requires approximately 10 µS conductivity / 5 ppm minimum and will not provide suitable measurements in pure or distilled water.

Do not use distilled water for long-term sensor storage.

After use:

• Rinse the electrode appropriately.

• Avoid scratching or damaging the sensing element.

• Keep the sensor properly hydrated.

• Store the instrument according to the manufacturer's electrode-storage recommendations.

Package Contents

A typical ORP-200 package includes:

• 1 × HM Digital ORP-200 ORP Meter

• 1 × Replaceable ORP Sensor / Electrode

• Batteries

• Protective Sensor Cap

• Lanyard

• User Manual

Package contents may vary by production revision or market.

Ideal For

HM Digital ORP-200 is ideal for:

• Water treatment professionals

• Laboratories

• Environmental testing

• Swimming pool professionals

• Aquarium owners

• Aquaculture operators

• Hydroponic growers

• Industrial water-treatment facilities

• Research laboratories

• Field technicians

• Water-quality testing professionals

Product Highlights for Website

Professional ORP Testing
Measure oxidation-reduction potential from -999 to +1000 mV.

Waterproof Construction
Submersible waterproof housing suitable for field and water-testing applications.

Replaceable Sensor
Replace the electrode instead of replacing the entire meter.

Digital Calibration
Convenient digital calibration with fine adjustment.

Temperature Measurement
Displays temperature along with ORP measurement.

Portable Design
Compact handheld meter suitable for laboratory and on-site testing.