What does the Hach DR300 measure?

The LPV445.97.00110 variant measures Free Chlorine and Total Chlorine in two ranges: Low Range (LR) 0.02-2.00 mg/L Cl2 using a 25mm glass sample cell, and High Range (HR) 0.1-8.0 mg/L Cl2 using a 1cm plastic sample cell. Free vs Total Chlorine is determined by the DPD reagent used, not an instrument setting. The DR300 family is available in 15+ parameter configurations including bromine, nitrate, phosphate, iron, zinc, ozone, dissolved oxygen, and others.

How do I fix E-01 error on Hach DR300?

E-01 is an ambient light error. The instrument cap is not fully installed on the cell holder, allowing ambient light to reach the detector. Ensure the cap is completely and firmly seated before pressing Zero or Read. If the error occurs during zeroing, zero the instrument again after fully seating the cap. If it recurs in bright environments, shade the instrument from direct sunlight or fluorescent light during measurement.

What reagents does the Hach DR300 chlorine model use?

The DR300 chlorine model (LPV445.97.00110) uses Hach DPD reagents. For Free Chlorine LR tests: DPD Free Chlorine Reagent Powder Pillows, 10 mL (Hach item 2105569). For Total Chlorine LR tests: DPD Total Chlorine Reagent Powder Pillows (contact Hach for current item number). Reagents are NOT included with the Americas version (LPV445.97.00110) and must be purchased separately. The EU/International version (LPV445.99.00110) includes reagents. Always use Hach reagents to maintain USEPA method validity.

Is the Hach DR300 waterproof?

Yes. The DR300 carries an IP67 rating, which means it is waterproof at 1 meter depth for up to 30 minutes, provided the battery compartment cover is fully closed and locked with a coin. The IP67 rating does not protect against high-pressure water jets. The instrument can be rinsed under running water for cleaning.

Product Review & Technical Reference — Hach

Hach DR300 Pocket Colorimeter: Complete Review & User Reference (2026)

Source: Official Hach User Manual DOC022.97.90639, Edition 5 (09/2021) • hach.com

Part No. LPV445.97.00110 (Americas) • Free & Total Chlorine LR/HR • IP67 Waterproof • Bluetooth® Claros

Hach DR300 Pocket Colorimeter front view showing LCD display reading 0.00 mg/L Cl2 chlorine

Water treatment operator using Hach DR300 pocket colorimeter in the field at a pump station

Hach DR300 Pocket Colorimeter — LPV445.97.00110

Free & Total Chlorine, LR/HR, IP67 waterproof, Bluetooth® Claros connectivity. USEPA Methods 8021 & 8167. Reagents sold separately.

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Part Number

LPV445.97.00110

LR Range

0.02–2.00 mg/L Cl₂

HR Range

0.1–8.0 mg/L Cl₂

IP Rating

IP67 Waterproof

Battery Life

~5,000 tests (4× AAA)

Data Storage

50 measurements

Connectivity

Bluetooth® (dongle optional)

EPA Methods

8021 (Free) • 8167 (Total)

What the DR300 Is and Who Uses It

The Hach DR300 is a portable filter photometer — a single-parameter pocket colorimeter that measures chlorine concentration in water using Hach’s DPD (N,N-diethyl-p-phenylenediamine) reagent chemistry. It is IP67 waterproof, fits in a shirt pocket, runs on 4 AAA batteries for approximately 5,000 tests, and can wirelessly transmit data to Hach’s Claros cloud platform via an optional Bluetooth dongle. The DR300 continues Hach’s Pocket Colorimeter line that has been in continuous production since 1993.

This specific variant (LPV445.97.00110) is factory-configured for Free Chlorine and Total Chlorine in two ranges. The same instrument body is available in 15+ parameter configurations including bromine, nitrate, phosphate, iron, ozone, dissolved oxygen, and zinc — all sharing the same keypad, IP67 enclosure, and Claros connectivity.

Application Sector	Typical Use Case
Municipal drinking water	Residual chlorine verification in distribution systems; EPA and state compliance monitoring
Wastewater treatment	Effluent disinfection verification; regulatory compliance before discharge
Swimming pools and spas	Free and total chlorine monitoring; combined chlorine (chloramine) calculation; public facility compliance
Food and beverage processing	Sanitation verification in clean-in-place (CIP) systems; process water quality
Industrial cooling towers	Biocide residual monitoring to control Legionella and biofilm growth
Field and laboratory	General water quality analysis; field verification of lab results; remote site testing

Measurement Ranges — LR vs HR and the Critical Cell Selection Rule

Range	Parameter	Measurement Range	Sample Cell Required	USEPA Method
LR (Low Range)	Free Chlorine	0.02–2.00 mg/L Cl₂	25 mm (10 mL) GLASS	USEPA 8021
LR (Low Range)	Total Chlorine	0.02–2.00 mg/L Cl₂	25 mm (10 mL) GLASS	USEPA 8167
HR (High Range)	Free Chlorine	0.1–8.0 mg/L Cl₂	1 cm (10 mL) PLASTIC	DPD HR method
HR (High Range)	Total Chlorine	0.1–8.0 mg/L Cl₂	1 cm (10 mL) PLASTIC	DPD HR method

Cell selection is mandatory, not optional. Use the 25 mm GLASS cell for LR tests. Use the 1 cm PLASTIC cell for HR tests. Using the wrong cell for the selected range produces inaccurate results. The Range key selects LR or HR — always confirm the correct range before zeroing. Free vs Total Chlorine is determined by the DPD reagent used, not an instrument setting.

Complete Technical Specifications

Specification	Detail
Product number	LPV445.97.00110 (Americas) • LPV445.99.00110 (EU/International — includes reagents)
Instrument type	Portable filter photometer (single-parameter pocket colorimeter)
Dimensions	6.9 × 15.7 × 3.4 cm (2.7 × 6.2 × 1.3 in.)
Weight	0.25 kg (0.55 lb)
IP rating	IP67 — waterproof at 1 m for 30 minutes (battery compartment closed and locked)
Light source	LED (fixed wavelength ±2 nm; factory-calibrated for chlorine)
Detector	Silicon photodiode
Filter bandwidth	15 nm
Absorbance range	0 to 2.5 Abs (E-15 error above 3.5 Abs)
Display	LCD with backlight
Power	4 × AAA alkaline batteries — NO rechargeable batteries; ~5,000 tests (backlight reduces life)
Data storage	Last 50 measurements with time stamp; oldest overwritten after 50; cannot delete manually
Bluetooth®	Via optional Hach Communication Dongle (LPV446.99.00012); enables Claros connectivity
Operating temperature	0 to 50 °C (32 to 122 °F); 0–90% RH non-condensing
Storage temperature	−20 to 55 °C (−4 to 131 °F); 0–80% RH non-condensing
Certifications	CE • FCC Part 15 Class B • ICES-003 Class B
Warranty	1 year (EU: 2 years)

What Is and Isn’t Included (LPV445.97.00110 Americas)

Item	Included?	Notes
DR300 instrument	Yes	Factory-configured for Free + Total Chlorine, LR/HR
4 × AAA alkaline batteries	Yes	Pre-installed or included; do not substitute rechargeable
25 mm (10 mL) glass sample cells ×6	Yes	For LR tests; handle carefully — glass cells are fragile
1 cm (10 mL) plastic sample cells ×2	Yes	For HR tests; more impact-resistant than glass
Storage/carrying case	Yes	Rigid case for field transport; houses instrument, cells, accessories
DPD Reagents	NOT included	Must be purchased separately from Hach (see reagents section below)
Hach Communication Dongle (Bluetooth)	NOT included	Optional; sold separately as LPV446.99.00012

Keypad & Display Reference

Key	Measurement Mode	Menu Mode
Range (top-left)	Switches between LR and HR	Scroll UP / hold 3 sec to ENTER menu
Zero (middle-left)	Sets instrument zero (blank)	Back one level / hold 3 sec to EXIT menu
Power (bottom-left)	Turns instrument ON/OFF	Hold 5 sec to RESET (calibration preserved)
Backlight (top-right)	Toggles LCD backlight	Scroll DOWN / decrease digit value
Read (bottom-right)	Starts measurement	SELECT / advance to next digit

Display Element	Meaning
Numeric display	Measured value in mg/L Cl₂, absorbance, or menu codes
Range arrow icon	Points to the currently active range (LR or HR)
Battery icon flashing	Low battery — replace all 4 AAA batteries immediately; results may be inaccurate
Bluetooth® icon	Communication Dongle installed and Bluetooth active
Calibration adjusted icon	SCA or user-entered calibration curve is active (not factory default)
Flashing numeric result	Reading is outside the instrument range — do not use this value; dilute or switch range

14-Step Test Procedure

Safety note: Wear appropriate PPE when handling DPD reagents. Consult the reagent SDS before use. Dispose of reagent waste per local regulations. If this instrument is used for regulatory compliance monitoring, the operator is responsible for ensuring testing meets all applicable regulatory requirements.

Select range

Press Range to toggle LR or HR. Select LR (0.02–2.00 mg/L) for drinking water; HR (0.1–8.0 mg/L) for pool water or high-concentration dosing points.

Prepare the blank

Follow the downloaded Hach test procedure for blank preparation. Typically: same water as the sample, without reagent added. Download procedures at hach.com → Search “DR300” → Downloads → Methods/Procedures.

Clean the blank cell

Wipe the outside of the blank sample cell with a clean, no-lint cloth. Remove all fingerprints, water droplets, and debris from the optical surface.

Insert the blank cell

Place blank cell in the cell holder. Align the orientation mark on the cell with the reference mark on the instrument. Consistent orientation improves repeatability.

Install the instrument cap — critical

Place the cap fully over the cell holder. It must be completely seated to block all ambient light. Incomplete seating causes E-01 errors every time.

Zero the instrument

Press Zero. Display shows “––––” then “0.00”. This establishes the baseline with the blank. If zero fails, an error code will display.

Remove blank cell

Take the blank cell out of the holder. Keep it — you may need it to re-zero during the test session.

Prepare the sample

Add the correct DPD reagent to the sample cell per the test procedure. Free Chlorine and Total Chlorine require different DPD reagents. Use the correct one for the parameter being measured.

Clean the sample cell

Wipe the outside of the reacted sample cell thoroughly with a no-lint cloth. Any reagent residue on the optical surface will affect the result.

Insert the sample cell

Place the reacted cell in the holder in the same orientation as the blank was inserted.

Install the cap again

Place the cap fully over the cell holder before pressing Read. This is the same step that causes most E-01 errors when skipped or not fully seated.

Press Read and record

Press Read. Result displays in mg/L Cl₂ and is automatically stored in memory with a time stamp. If the result flashes: it is outside the instrument range. Out-of-range high: dilute the sample, confirm the correct range. Out-of-range low: verify cap is fully installed, re-zero.

Remove sample cell

Take the cell out of the holder promptly after recording the result.

Rinse the cell and cap

Immediately rinse both cell and cap three times with deionized or distilled water. Use tap water if tap concentration is lower than the sample concentration. Do this immediately — dried DPD reagent is difficult to remove.

Free + Total Chlorine in one session: Measure Free Chlorine using DPD Free reagent. Record result. Measure Total Chlorine on a separate sample using DPD Total reagent. Combined chlorine (chloramines) = Total Cl₂ − Free Cl₂. The Range key only switches LR/HR — it does NOT switch between Free and Total parameters. That switch is made by changing the reagent.

Error Code Reference — All Codes

Code	Name	Cause	Solution
E-00	No Zero	Sample measured before zeroing in calibration mode	Measure a blank to zero the instrument first
E-01	Ambient light	Instrument cap not fully installed — ambient light reaching the detector	Ensure cap is fully and firmly seated before zeroing or reading. Re-zero after seating cap.
E-02	LED error	LED light source unstable or insufficient output	Replace all 4 batteries immediately. If LED still fails after battery replacement: contact Hach.
E-03	SCA error	Standard value outside SCA adjustment limits or entered concentration doesn’t match measured standard	Prepare fresh standard. Verify entered concentration is correct and within SCA limits.
E-04 (flashing)	Out of range	Measured value exceeds or is below the instrument range for the selected range	High: dilute sample and retest, or switch to HR. Low: verify cap is fully installed; re-zero.
E-06	Absorbance error	Absorbance value incorrect in user calibration, or fewer than 2 calibration points entered	Re-enter or re-measure absorbance. Ensure minimum 2 data pairs for any calibration curve.
E-07	Duplicate standard	Duplicate concentration entered in user calibration curve	Enter a unique concentration value for each calibration point.
E-09	Flash error	Instrument cannot save data to memory	Hold Power key 5 sec to reset. If persists: contact Hach.
E-10	Temperature range	Ambient temperature outside 0–50 °C operating range	Move instrument to within specified operating temperature before testing.
E-12	Low battery	Battery power too low for reliable operation	Replace all 4 AAA alkaline batteries. Do not continue testing — results may be inaccurate.
E-13	Parameter load failure	Instrument memory defective or corrupted	Contact Hach technical support. Cannot be resolved by user.
E-14	Zero invalid	Zero measurement too low — cell may be empty or improperly installed	Use a properly filled cell and re-zero. If continues: contact Hach.
E-15	Absorbance too high	Absorbance exceeds 3.5 Abs maximum	Check for light blockage in cell holder. Dilute sample to bring within range.
E-20	Signal out of range	Excessive ambient light reaching the detector	Ensure cap is fully installed. If persists: contact Hach.
E-21	Signal unstable	Fluctuating ambient light near the cell holder	Ensure cap is installed. Shield from fluctuating light sources. Repeat test.
E-22	Hardware error	Electronic system defective	Contact Hach technical support. Cannot be resolved by user.
E-30	No application (firmware)	Error during application firmware update	Re-update firmware via Hach Communication Dongle and Claros software.
E-31	Bootloader update failed	Error during bootloader transmission	Re-update bootloader.
E-32	Application update failed	Error during application transmission	Re-update instrument firmware.
E-66	Defective instrument	Instrument cannot accept firmware update	Contact Hach technical support — may require service or replacement.

Replacement Parts & Reagents

Description	Qty	Hach Item #
AAA alkaline batteries	4/pkg	4674300
Instrument cap (cell holder cover)	1	LPZ445.99.00006
Battery cover	1	LPZ445.99.00007
Sample cell, 25 mm glass — LR tests	6/pkg	2427606
Sample cell, 1 cm plastic — HR tests	2/pkg	4864302
Hach Communication Dongle (Bluetooth® / Claros)	1	LPV446.99.00012
Soft-sided carrying case / holster	1	5953100

Reagent	Application	Hach Item #
DPD Free Chlorine Reagent Powder Pillows, 10 mL, 100/pkg	Free Chlorine LR (0.02–2.00 mg/L); USEPA Method 8021	2105569
DPD Total Chlorine Reagent Powder Pillows, 10 mL	Total Chlorine LR (0.02–2.00 mg/L); USEPA Method 8167	Contact Hach
DPD HR Reagents (Free and Total, High Range)	HR tests (0.1–8.0 mg/L)	Contact Hach or distributor
Reagents are NOT included with the Americas version (LPV445.97.00110). Always use Hach reagents to maintain USEPA method validity and factory calibration.

DR300 Parameter Family — All Models

Each DR300 is a single-parameter instrument factory-configured at the time of purchase. All share the same IP67 body, keypad, and Bluetooth capability.

Product #	Parameter	Notes
LPV445.97.00110	Chlorine, Free + Total, LR/HR	This instrument — 0.02–2.00 mg/L LR; 0.1–8.0 mg/L HR
LPV445.97.62110	Chlorine, Free + Total, MR/HR	0.05–4.00 mg/L MR; 0.1–10.0 mg/L HR
LPV445.97.12110	Chlorine + pH	Chlorine 0.1–10 mg/L; pH 6–8.5
LPV445.97.01110	Bromine	Pool and spa bromine monitoring
LPV445.97.02110	Nitrate	Nitrate in water
LPV445.97.03110	Dissolved Oxygen	—
LPV445.97.04110	Ozone	Ozone residual measurement
LPV445.97.06110	Orthophosphate	Phosphate in water
LPV445.97.09110	Zinc	—
LPV445.97.10110	Molybdenum LR/HR	—
LPV445.97.15110	Manganese HR	—
LPV445.97.16110	Iron (TPTZ)	—
LPV445.97.22110	Iron (FerroVer®)	—
Various	Aluminum, Ammonia, Chlorine dioxide, Monochloramine, others	Contact Hach for full current parameter list