What is the difference between the Hach DR1900 and the DR900?

The DR900 is a multiparameter colorimeter using four fixed LED wavelengths (420, 520, 560, 610 nm). The DR1900 is a true VIS spectrophotometer with a xenon flash lamp covering the full 340-800 nm range, selectable to any wavelength at 1 nm resolution with 5 nm spectral bandwidth. The DR1900 adds multi-wavelength mode (up to 4 simultaneous wavelengths), time course mode for reaction kinetics, 50 operator IDs (vs 10), 100 sample IDs (vs 10), My Workflow for parallel multi-sample collection, password protection, and the optional Verification Kit LZV537 for traceable QA checks. The DR1900 is the choice when you need full spectrophotometric capability, time course analysis, or a larger ID and data management system.

What wavelength range does the Hach DR1900 cover?

The Hach DR1900 covers 340 to 800 nm visible spectrum using a xenon flash lamp light source. Wavelength selection is fully automatic based on the selected method, or manually selectable to any wavelength at 1 nm resolution with 5 nm spectral bandwidth. Stray light is less than 0.5% T at 340 nm. The xenon flash lamp requires no warm-up period and provides consistent spectral output across the full range.

What sample cells does the Hach DR1900 accept?

The DR1900 accepts a wide range of sample cell types through four interchangeable adapters (A, B, C, D): 1-inch square cells (10 mL, 16 mm, 20 mm path length); round cells (13 mm and 25 mm diameter); flow-through cells; AccuVac ampuls; and custom cells up to 50 mm path length. The adapter is changed without tools by aligning the arrow on the adapter with the arrow on the cell compartment.

How many programs does the Hach DR1900 have?

The DR1900 comes with factory pre-installed stored programs covering a wide range of water quality parameters for drinking water, wastewater, and industrial applications. It also supports LCK/TNTplus vial methods and up to 100 user-defined programs with custom wavelengths, calibration formulas, result units, and up to 4 timers per program. Frequently used methods can be saved to Favorites for one-touch access.

What is My Workflow on the Hach DR1900?

My Workflow is a DR1900 feature for field teams collecting multiple samples simultaneously from different monitoring locations. It creates a named batch with sequentially numbered tabs (one per sample location). The operator uses left/right arrows to switch between sample tabs and performs Zero and Read operations for each sample independently. Tab names can be customized with location names. My Workflow is particularly valuable for operators monitoring multiple sampling points in a single field visit, keeping all readings organized within a single named batch in the data log.

Product Review & Technical Reference — Hach

Hach DR1900 Portable Spectrophotometer: Complete Review & Reference (2026)

Name: Hach DR1900 Portable Spectrophotometer Review
Item: Hach DR1900 Portable VIS Spectrophotometer
Rating: 4.7
Author: Commercial Water Lab

Source: Hach DR1900 User Manual DOC022.53.80343, Edition 2 (August 2017) • DOC0229780343

340–800 nm Xenon Flash Lamp • IP67 • 500-Point GLP Data Log • 50 Operator IDs • 100 Sample IDs • Multi-Wavelength & Time Course Modes

Water treatment operator using Hach DR1900 portable spectrophotometer at a field site in winter conditions

Hach DR1900 Portable VIS Spectrophotometer

340–800 nm • Xenon flash lamp • IP67 • 500-point GLP log • 50 operator IDs • Multi-wavelength & time course modes. Ships with 4 cell adapters and matched 1-inch cell pair.

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Wavelength Range

340–800 nm

Light Source

Xenon flash lamp

Spectral Bandwidth

5 nm

Wavelength Resolution

1 nm

Photometric Accuracy

±3 mAbs at low Abs

Linearity

<0.5% to 2 Abs

Stray Light

<0.5% T at 340 nm

IP Rating

IP67 (cover closed)

Data Log

500 results (GLP)

Operator IDs

Up to 50

Sample IDs

Up to 100

Power

4× AA batteries

Weight

1.5 kg

Dimensions

178 × 261 × 98 mm

User Programs

Up to 100

Manual

DOC022.53.80343 Ed.2

DR1900 vs DR900 — Colorimeter vs Spectrophotometer

The most important distinction in the Hach portable instrument lineup is the difference between a colorimeter (DR300, DR900) and a spectrophotometer (DR1900). Both measure the absorbance of colored solutions to determine analyte concentration — but they do so in fundamentally different ways that affect capability, accuracy, and appropriate application.

COLORIMETER vs SPECTROPHOTOMETER — KEY DIFFERENCES

DR900 Colorimeter

Fixed LED wavelengths: 420, 520, 560, 610 nm only
Automatic wavelength selection from 4 options
10 operator IDs / 10 sample IDs
500-result data log
No multi-wavelength mode
No time course mode
No password protection
No wavelength scan capability
Lower instrument cost
Best for: routine single-parameter monitoring with established methods

DR1900 Spectrophotometer

Full 340–800 nm range, any wavelength at 1 nm steps
Xenon flash lamp — no warm-up, consistent output
50 operator IDs / 100 sample IDs
500-result GLP data log
Multi-wavelength mode (up to 4 simultaneous)
Time course mode (reaction kinetics, BOD)
Password protection for calibration/programs
My Workflow for parallel sample batches
Verification Kit LZV537 for traceable QA
Best for: multi-parameter field labs, compliance monitoring, custom method development

Feature	DR300 (Single-Param)	DR900 (Colorimeter)	DR1900 (Spectrophotometer)
Wavelength type	1 fixed LED	4 fixed LEDs	340–800 nm continuous
Light source	LED	LED (4×)	Xenon flash lamp
Spectral bandwidth	Narrow LED	Narrow LED	5 nm
Multi-wavelength mode	No	No	Yes (up to 4 λ)
Time course mode	No	No	Yes
My Workflow	No	No	Yes
Operator IDs	None	10	50
Sample IDs	None	10	100
Password protection	No	No	Yes
User programs	None	10	100
Verification kit support	No	No	Yes (LZV537)
IP rating	IP67	IP67	IP67 (cover closed)
Power	4× AAA	4× AA	4× AA

Optical Engine — Xenon Flash Lamp Technology

The xenon flash lamp is what separates the DR1900 from LED-based colorimeters at the fundamental physics level. Instead of selecting from a handful of discrete LED wavelengths, the xenon lamp produces a continuous, high-intensity broadband output across the full 340–800 nm visible spectrum with each flash. A diffraction grating then separates this white light, and a slit selects the precise measurement wavelength at 1 nm resolution.

Why Xenon Over LED or Tungsten-Halogen

No warm-up period needed — xenon flash reaches full output instantly. Extended lamp lifetime vs tungsten-halogen. Low power consumption compatible with battery operation. High-intensity pulses produce stray light below 0.5% T at 340 nm — better than most bench-top colorimeters.

Spectral Bandwidth & Resolution

5 nm spectral bandwidth at 1 nm wavelength resolution means the DR1900 can discriminate overlapping spectral peaks that LED colorimeters at fixed wavelengths cannot. This is the critical capability for multi-component analysis and custom method development.

Sample Cell Compatibility — Complete Reference

The DR1900 accepts more sample cell formats than any other instrument in the DR portable series, through four interchangeable adapters (A, B, C, D). The adapter is changed without tools by aligning the arrow on the adapter top surface with the arrow on the cell compartment rim. Always verify the correct adapter is installed before beginning measurements — the wrong adapter shifts the optical path and invalidates results.

Adapter	Cell Type	Dimensions / Volume	Common Use
A	1-inch square rectangular cell	10 mL, 10 mm path	Most Hach stored programs; ships as standard matched pair with instrument
A	16 mm round cell	Varies by method	LCK/TNTplus vial methods
B	13 mm round cell	Varies	Select reagent kit methods
B	25 mm round cell (1-inch)	10 mL	DR300-compatible methods (DPD chlorine, FerroVer iron, PhosVer phosphate)
C	20 mm square cell	Varies	High-path-length methods for trace analysis
C	Flow-through cell	Continuous flow	On-line process monitoring configurations
D	50 mm path length cell	Large volume	Ultra-trace analysis requiring extended path length for sensitivity
No adapter	AccuVac® ampuls	Self-fill vacuum ampuls	Methods with AccuVac format reagents (chlorine, phosphate, iron, others)
Adapter orientation: align arrow on adapter with arrow on cell compartment rim. Replace without tools at any time.

Protective cover required in bright light. When the sample cell cover is open for open-top cells or flow-through configurations, install the included protective cover over the cell compartment to prevent stray ambient light from entering the optical path. Stray light in bright sunlight without the protective cover is the most common cause of erratic readings in field conditions.

Standard Measurement Workflow

Power on — no warm-up required

Press POWER. The xenon flash lamp reaches full output immediately — no warm-up delay unlike tungsten-halogen sources. The reading screen displays the last used program and current battery level.

Select program from Stored Programs, LCK/TNTplus, or Favorites

Press SETTINGS → All Programs/Methods. Search by number (Select by number) or alphabetically (Select by letter). For frequently used methods, add to Favorites first for one-touch access from the home screen. Press Start to activate the selected method.

Assign Operator ID and Sample ID

Press Options → Operator ID to select the active operator. Press Options → Sample ID to assign the sample location. Both are tagged to every reading stored in the data log. For sequential repeat samples from the same location, the instrument auto-increments the sample number (e.g., River_A (001), River_A (002)).

Zero with blank cell — sample matrix compensation

Fill the appropriate cell with sample water (no reagent). Wipe the exterior with a lint-free cloth. Insert cell with correct adapter installed. Press Zero (RIGHT selection key). The instrument subtracts the sample matrix absorbance from subsequent readings — critical for turbid or colored samples where the matrix itself contributes absorbance.

Prepare sample cell with reagent per method procedure

Follow the specific method document for reagent type, quantity, mixing procedure, and reaction time. Reaction times are not suggestions — color development is time-dependent. Wipe the exterior clean with a lint-free cloth before inserting.

Insert sample cell — verify adapter — press Read

Confirm the correct adapter is installed for the cell type in use. Insert the reagent cell. Close the sample cell cover (maintains IP67 rating). Press Read. Result displays in the configured unit with the active wavelength shown on screen.

Reading is auto-stored to GLP data log

Every reading is automatically saved with: result value and unit, measurement date and time, sample ID, operator ID, program name and number. Data log capacity is 500 readings on a FIFO basis. Export via USB before the log fills to preserve records.

Over-range: “+++” / Under-range: “---”

+++: concentration exceeds the method upper limit — dilute sample with reagent-demand-free water, retest, multiply result by dilution factor. ---: below detection limit — verify reagent addition, check reagent expiry, confirm procedure was followed correctly.

Three Advanced Photometer Modes

Beyond stored program selection, the DR1900 provides three flexible photometer function modes for experienced operators performing measurements outside the pre-programmed library. Access via SETTINGS → Photometer Functions.

Single Wavelength Mode — Direct Photometric Reading

Takes a direct absorbance or transmittance reading at one operator-specified wavelength. Navigate: SETTINGS → Photometer Functions → Single Wavelength → Options → Advanced Options. Set wavelength (340–800 nm, 1 nm steps), result unit (Abs or %T), and resolution. Use for custom reagent methods not in the stored program library, or for rapid screening at a known parameter wavelength. All readings stored to the GLP data log with Operator ID and Sample ID tags.

Multi Wavelength Mode — Up to 4 Simultaneous Wavelengths

Measures absorbance at up to four user-defined wavelengths simultaneously and applies a mathematical formula to combine the results. Navigate: SETTINGS → Photometer Functions → Multi Wavelength → Options → Advanced Options → λ1–λ4. Applications: multi-component analysis (e.g., measuring two analytes that absorb at different wavelengths in the same sample), interference correction (subtracting background absorbance at an off-peak wavelength), and ratio calculations. This is the capability that separates the DR1900 from all colorimeters in the Hach portable lineup — no fixed-wavelength instrument can perform this function.

Time Course Mode — Reaction Kinetics & BOD Monitoring

Records absorbance automatically at regular intervals over a defined time period. Navigate: SETTINGS → Photometer Functions → Time Course → Options. Set wavelength, interval, and duration. Applications: biochemical oxygen demand (BOD) monitoring via absorbance correlation over time; reaction kinetics for non-equilibrium colorimetric methods; disinfection rate monitoring; biological treatment process tracking. Time course data is plotted on-screen during acquisition and stored in the data log as a series of timed readings.

My Workflow — Parallel Multi-Sample Field Collection

My Workflow is the DR1900 feature most valuable to field teams collecting multiple samples simultaneously from different monitoring locations. It allows a single operator to manage a named batch of samples — each in its own numbered tab — without mixing up which reading belongs to which location.

Create a new workflow: SETTINGS → My Workflow → Options → New My Workflow

Select the analytical program, enter the total number of samples in the batch, and assign a workflow name. The instrument creates sequentially numbered tabs prefixed with the workflow name.

Use LEFT/RIGHT arrows to switch between sample tabs

Each tab is independent — perform Zero and Read operations for each tab as samples are processed. There is no requirement to complete samples in order; toggle between tabs at any time.

Customize tab names with location identifiers

Press Options → Edit My Workflow to rename tabs from sequential numbers to meaningful location names (e.g., "Inlet," "Basin 1," "Effluent"). Renamed tabs persist throughout the workflow session.

All readings stored as a named batch in the data log

Every reading in the workflow is tagged with the workflow name and tab identifier, keeping the complete batch organized as a unit in the 500-point GLP data log. Press Options → Delete My Workflow to remove a completed workflow.

My Workflow field scenario: An operator monitoring six sampling points along a river reach can create a "River_Survey_06-18" workflow with six tabs named for each location. All six chlorine residuals are measured in one session, each reading auto-tagged to the correct location, and the complete batch exported to CSV via USB at the end of the field day — with full operator attribution and timestamps on every result.

Operator ID & Sample ID — GLP Data Traceability

Feature	DR300	DR900	DR1900
Operator IDs	None	10	50
Sample IDs	None	10	100
Auto-sequential numbering	No	No	Yes — River_A (001), (002)…
GLP metadata per result	None	Basic	Value, unit, date, time, operator ID, sample ID, program name/number

To manage Operator IDs: press Options → Operator ID from the reading screen. Create, select, or delete IDs (maximum 50). To manage Sample IDs: press Options → Sample ID. Create, select, or delete IDs (maximum 100). Sequential numbering is applied automatically for repeat samples — each new reading from the same location increments the counter without manual re-entry.

User Programs — 100 Custom Methods

The DR1900 supports up to 100 user-defined programs, allowing laboratories to create validated custom methods for parameters not covered by the factory-stored program library or to modify existing methods for site-specific matrix corrections.

Navigate: SETTINGS → Favorites/User Programs → User Programs → New Program

Opens the user program creation interface.

Define program parameters

Set: program name; measurement wavelength (any wavelength 340–800 nm at 1 nm steps); result unit; result resolution; chemical formulas for concentration calculation (up to 4 formulas); calibration formula; upper and lower reporting limits.

Add timers (up to 4 steps)

Each user program can include up to 4 timed steps with countdown prompts — essential for methods with mandatory reaction times between reagent additions or between mixing and reading.

Save and add to Favorites

The program is saved to the User Programs list. Add to Favorites for immediate access from the home screen without navigating the full program library.

Quality Assurance — Three Optical System Checks

The DR1900's built-in optical check routines allow in-field verification of instrument performance without external calibration services. Access via SETTINGS → Setup → System Checks → Optical Checks. Run all three checks whenever a regulatory compliance program requires documented QA, after instrument repair or service, or whenever results appear anomalous.

Wavelength Check — Accuracy at 807 nm

Navigate: Optical Checks → Wavelength Check. Insert the Neodym or BG20/2 test filter as prompted. Follow on-screen prompts. Compare the result against the certified value for your specific filter. If outside tolerance, contact Hach — do not continue regulated measurements. The wavelength check is the primary verification that the optical system is properly calibrated.

Absorbance Check — Photometric Accuracy

Navigate: Optical Checks → Absorbance Check → Options → λ → enter the wavelength specified for your test filter. Insert the absorbance test filter. Compare against certified filter values. Out-of-tolerance results require manufacturer contact before any further regulated testing.

Stray Light Check — Must be <0.5% T

Navigate: Optical Checks → Stray Light Check. Insert the stray light test filter (NaNO₂ solution or equivalent) as prompted. Result must be less than 0.5% T to confirm the DR1900 meets its published specification. Stray light above 0.5% T at 340 nm will cause positive bias in measurements at low wavelengths.

Verification Kit LZV537 — Traceable QA Reference

The optional Verification Kit LZV537 provides the most comprehensive, traceable QA check available for the DR1900. It contains six precision glass filters with certified target values and tolerances for stray light, photometric accuracy, and wavelength accuracy across multiple wavelengths — enabling ISO 17025-compatible instrument verification documentation. Navigate: SETTINGS → Setup → System Checks → Optical Checks → Verification Kit. Recommended for all compliance monitoring programs and regulated laboratory applications.

Full Technical Specifications

Physical & Environmental

Specification	Value
Dimensions (L × W × H)	178 × 261 × 98 mm
Weight	1.5 kg
IP Rating	IP67 with sample cell cover closed (1 m submersion, 30 min)
Operating temperature	10–40°C
Storage temperature	−20 to +60°C (without batteries)
Relative humidity	10–90% non-condensing
Power source	4× AA alkaline or rechargeable NiMH (charging module optional)
Auto-shutoff	30 minutes (default); disabled when on AC power
Display	Backlit graphic LCD
Keypad	6-key: POWER, HOME, SETTINGS, BACKLIGHT, d-pad, 2 soft keys

Optical & Photometric

Specification	Value
Wavelength range	340–800 nm
Light source	Xenon flash lamp
Spectral bandwidth	5 nm
Wavelength resolution	1 nm
Wavelength accuracy	Verified by Wavelength Check procedure at 807 nm
Photometric accuracy	±3 mAbs at low absorbance values
Photometric linearity	<0.5% deviation up to 2 Abs
Stray light	<0.5% T at 340 nm
Photometric range	0–2.5 Abs (corresponding to approximately 0–99.7% T)
Warm-up time	None — xenon flash lamp reaches full output immediately

Data & Software

Specification	Value
Data log capacity	500 results (FIFO)
GLP metadata per result	Value, unit, date, time, operator ID, sample ID, program name, program number
Operator IDs	Up to 50 named IDs
Sample IDs	Up to 100 named IDs with auto-sequential numbering
User programs	Up to 100 custom programs
Data export	USB (type A) — data log exported as CSV file
Firmware update	Via USB from PC
Password protection	Setup menus, operator ID editing, K factor editing, user programs, My Workflow, data log deletion
Languages supported	Multiple — selectable via SETTINGS → Setup → Language

Maintenance Reference

Instrument Exterior

Clean with a moist cloth and mild soap. Wipe dry immediately. Do not use abrasive cleaners, solvents, or high-pressure water — these compromise the IP67 enclosure seal. The IP67 rating applies only when the battery compartment screws are properly tightened and the sample cell cover is fully closed.

Cell Compartment Cleaning

Never insert cloths or swabs into the optical cell compartment. The optical surfaces inside the compartment will be scratched by any contact with fibrous material, permanently degrading instrument performance. If liquid or debris enters the compartment: remove all adapters and cells, turn the instrument upside down, and use a rubber suction bulb to blow air gently into the compartment.

Sample Cell Cleaning

Cleaning Type	Procedure	When Required
Standard cleaning	Laboratory detergent (e.g., Liquinox) at recommended concentration; elevated temperature or ultrasonic bath; minimum 3 rinses with deionised water; air dry only — never paper towels on optical surfaces	After every use; standard parameters
Acid cleaning	Soak in dilute nitric or hydrochloric acid per method specification; rinse thoroughly with deionised water; wear acid-resistant PPE	Mandatory for all low-level metal determinations
Cell replacement	Discard cells with any visible scratch or optical etching — do not continue using scratched cells	When optical surfaces are scratched or permanently contaminated

Battery Replacement

Never store the DR1900 with batteries installed for extended periods. Expired batteries can cause hydrogen gas accumulation inside the sealed IP67 compartment. Replace all four AA batteries simultaneously — never mix new and used batteries or batteries from different brands. Tighten the battery compartment cover screws carefully after replacement — a correctly sealed battery cover is essential to maintain IP67 rating.

Troubleshooting Guide

Symptom	Likely Cause	Resolution
“+++” over-range	Sample concentration above method upper limit	Dilute with reagent-demand-free water; retest; multiply result by dilution factor
“---” under-range	Below detection limit; reagent not added; procedural error	Verify reagent addition; check procedure; verify reagent expiry; repeat test
Erratic readings in sunlight	Stray ambient light entering open cell compartment	Install the protective cover; shade the instrument from direct sunlight
High blank reading	Cell contamination; previous reagent carryover; scratched cell	Clean or replace the sample cell; use triple-rinse procedure before measurement fill
Inconsistent replicates	Reaction time not observed; insufficient mixing; cell not wiped; temperature variation	Follow method procedure exactly; wipe cell exterior before every insertion
Wavelength check failure	Optical system drift; damaged test filter; wrong filter inserted	Verify correct filter inserted per on-screen prompt; contact Hach if failure persists
Absorbance check out of tolerance	Xenon lamp degradation; contaminated cell compartment; wrong filter	Clean cell compartment with bulb; verify correct filter; contact Hach
Stray light >0.5% T	Optical system degradation; contaminated optical surfaces	Do not use for regulated measurements; contact Hach technical support
Will not power on	Dead or incorrectly installed batteries; battery compartment not sealed	Replace all 4 AA batteries; verify correct orientation; tighten battery cover screws
USB data export fails	Cable not fully seated; instrument powered off; USB driver issue	Reconnect cable with instrument powered on; use different USB port on PC; update firmware
Password forgotten	Administrator-level access needed	Contact Hach technical support — instrument may require factory reset

Replacement Parts & Optional Accessories

Standard Replacement Parts

Item	Notes
1-inch square matched cell pair (10 mL)	Ships with instrument; replace when scratched or etched
Cell adapters A, B, C, D	One set ships with instrument; order replacement if lost or damaged
Batteries, AA alkaline (4-pack)	Standard AA alkaline; do not use rechargeable without NiMH module
Protective cover (sample cell compartment)	Required for bright-light field operation with open-top cells
Dust cover	Ships with instrument; protects optical compartment during storage

Optional Accessories

Accessory	Purpose
Verification Kit LZV537	Six precision glass filters; certified values for stray light, photometric accuracy, and wavelength accuracy; required for ISO 17025 and regulatory QA documentation
NiMH Battery Charging Module	Enables use of rechargeable NiMH AA batteries; includes module and compatible NiMH cells
USB+Power Module	Enables AC power operation (disables auto-shutoff); also provides USB connectivity for data export
Flow-through cell	For continuous-flow or on-line sampling configurations; requires Adapter C
50 mm path length cell	For ultra-trace analysis requiring extended optical path for sensitivity; requires Adapter D
Wavelength check filter (Neodym or BG20/2)	For Wavelength Check QA procedure; purchase separately if not included with instrument
Stray light test filter (NaNO₂)	For Stray Light Check QA procedure

Applications — Drinking Water, Wastewater & Industrial

Sector	Key Parameters	Mode Used
Drinking water treatment	Free/combined/total chlorine; fluoride; nitrate/nitrite; iron; manganese; ammonia; turbidity surrogates; colour	Stored programs; LCK/TNTplus methods
Wastewater compliance	COD; total nitrogen; total phosphorus; BOD; suspended solids surrogates; heavy metals (lead, copper, zinc, chromium)	Stored programs; Time Course (BOD)
Cooling tower chemistry	Biocide residuals; phosphonate inhibitors; molybdate tracers; silica; hardness surrogates	Stored programs; Multi Wavelength (multi-component)
Boiler feedwater	Phosphate; silica; iron; dissolved oxygen surrogates; condensate quality	Stored programs; Single Wavelength (custom)
Industrial process water	Metal concentrations; sanitiser residuals; colour and clarity; application-specific parameters	User Programs; Multi Wavelength
Environmental monitoring	River and lake chemistry; stormwater quality; nutrient loading; trace metal surveys	My Workflow (multi-site); Stored programs