02 9543 7377


DDM 2909 Automatic Density Meter by Rudolph Research Analytical

The Rudolph DDM 2909 Automatic Density Meter features built-in Peltier Temperature Control of the Sample, Full Range Viscosity Correction, Reference Oscillator and VideoViewTM  for easy bubble detection, and is fully GMP/GLP Compliant. With the flexibility of Windows the DDM 2909 is Network ready with Internet connectivity allowing remote access to Rudolph Research Analytical’s Service and Technical Support Team.
The 2909 comes complete with 20 Density to concentration tables which include Brix, Alcohol, API, and many various laboratory reagents. An unlimited number of additional tables, polynomials, and formulas may be added.

Flexible Method Management

Factory installed density meter measurement methods allow for immediate selection of the correct method to match the most common applications.
Automatic Density Meter Method Management Screen
For unique Density Meter measurement applications, create a sample method using Concentration Tables, Formulas, and Polynomials to match the density measurement methods used in your laboratory. Just a few of the many possible customized sample methods shown below:

  • Baumé of Hydrochloric Acid
  • Normality of Sulfuric Acid
  • Density of Gases and Aerosols
  • Drug to Propellant Ratio
  • Lead Content
  • ppm Gold in Acid
  • % Toluene in Heptane
  • Fat in Lubricant
  • Mole Fraction of Methanol
  • % HNO3
  • Monomer Solutions
  • Potassium Permanganate
  • Hydrogen Peroxide
  • Molar Solutions of EDTA
  • SG of Urine
  • Sweeteners
  • Sodium Hydroxide

Setting up your custom method on your Density Meter is as simple as filling out a few screens like the one below:
Automatic Density Meter Methods Screen

Full Feature VideoView™

VideoView™  provides superior high resolution visual bubble detection within your samples with live on-screen video viewing.  Rudolph’s industry leading 10X magnification aids in identifying bubbles if present in the sample.
The video clarity, magnification, and resolution mean no more straining to see small difficult-to-detect air bubbles in your sample. Rudolph’s exclusive VideoView™  is protected under Patent #7,437,909.

Oscillating U-Tube with Viscosity Correction and Reference Oscillator

The DDM 2909 Density Meter’s oscillating U-tube with full range viscosity correction and reference oscillator allows long term calibration stability and measurement at all temperatures with a single calibration.

Computer Windows Based Flexibility

  • 32 gigabytes of internal Compact Flash Memory .
  • The DDM 2909 Density Meter is network ready and data may also be saved directly to your server or to any directory desired.
  • Internet access is possible directly from the DDM 2909’s touch screen.
  • Disk Protection feature protects the operating system against malware infections in networked environments.
  • Windows based navigation architecture is so intuitive that most operators will never read the manual. But should you wish to reference the manual, it is stored right on the DDM 2909’s internal memory
  • Copy methods, transfer concentration tables, download data, etc., via the USB ports.
  • Five USB ports allow for quick and easy connection to a mouse, keyboard, printer, bar code scanner, or memory stick.

Density Meter File Export

Versatile Communication Capability

The DDM 2909’s standard communication package includes:

  • Touch Screen User Interface
  • 5 USB ports (3 Rear, 2 Front)
  • 1 – Ethernet Cat 5 Port
  • 2 RS 232 Ports
  • Keyboard, Bar Code Scanner, Mouse, Network Capabilities, Memory Stick.

Allowing the capability to:

  • Connect Directly to Rudolph Service and Technical Support
  • Connect to any Windows® based Printer via USB or direct to the server via Windows® Print Library
  • Save measurement data locally and directly to your Network/Server.

cGMP/GLP Printing

Sample measurement reports are edited quickly and easily. Just import your logo to the DDM 2909 Density Meter and print your company’s customized “C of A” directly.

Standard Accessories

The DDM 2909 standard accessories include:

  • Quick Start Guide
  • Rinse/Sample Waste Container
  • Filling Nozzles
  • Luer Syringes
  • Connecting Fittings & Tubing
  • Manual
  • Drying Pump:  Built in Drying Pump used to quickly dry the cell after rinsing and prior to the next measurement,reducing total sample analysis time.  Air drying hose positioned intelligently so as not to become soiled withsample and rinse solvents.


All Rudolph Instruments carry our exclusive 20 Commitment to service your instrument.

Rudolph Research Analytical offers a comprehensive range of Preventive Maintenance and Service Programs. Rudolph has demonstrated a commitment to its customers by keeping installed instruments operational, not only for 20 years, but in some cases for over 40 years. This long-term commitment to keeping our instruments running makes the cost of ownership, over the life of a Rudolph Instrument, one of the lowest in the laboratory market segment. At the date this document was published, there is no other laboratory instrument manufacturer guaranteeing service and technical support for 20 years. View the entire 20 Service Guarantee. 


Measurement Ranges Density: 0 to 3 g/cm³ Temperature: 15°C to 60°C (controlled via Peltier) Pressure: 0 to 10 bars
Measurement Modes Continuous, Single, Multiple
Measurement Technique Mechanical Oscillator Method
Accuracy Density: 0.0002 g/cm³ with a single calibration at the measurement temperature Density: 0.0003 g/cm³ with a single calibration and measurement through multiple temperatures Temperature: 0.05°C
Repeatability Density: 0.0001 g/cm³ (Extra Resolution Available) Temperature: 0.02°C
Resolution Density: 0.0001 g/cm³ (Extra Resolution Available) Temperature: 0.01°C
Minimum Sample Volume Less than 1 mL
Wetted Materials Borosilicate glass, Teflon (PTFE, ECTFE)
Operating System Windows Embedded® safe from malware and viruses
Display 10.4 inch diagonal TFT type LCD with wide viewing angle, anti-glare flat panel touch screen, 300 nits brightness, 800 x 600 pixels, chemical and scratch resistant monitor, the industry's largest and most flexible interface
Communication Interface Touch Screen User Interface 5 - USB Ports (3 Rear - 2 Front) 2 - RS232 Ports Ethernet Port for Network Connection, Keyboard, Bar Code Scanner, Mouse, Network Capabilities
Video Scanning & Magnification Video assisted, capable of approximately 10X magnification.
Internal Memory 32GB Non-removable Compact Flash
Operating Dimentions 18.00" (L) 11.00" (W) 21.00" (H) 46cm (L) 28cm (W) 53cm (H)
Shipping Weight 46 lbs. (22 Kg)
Power Supply 85 to 260 VAC; 48 to 62 Hz
Power Consumption 150 - 200 Watts




Density Meter Loading Options

Vertical Load – A Rudolph Exclusive Feature

• Helps with sample injection is done against gravity. Suitable for left and right handed operators as opposed to manual horizontal injection. Plunger is easier to push with all samples and there is more control over the syringe than with Horizontal Load.

• Gives the ability to apply more pressure to the syringe when injecting viscous samples without harming operators.

• Much easier cleaning. When a measurement is complete and the syringe is removed, gravity will force the sample down and into the waste jar. As opposed to the traditional horizontal load, if the waste tubing was bent, the sample would pour backwards and spill out on the table.

• Preserves the nozzles and nozzle bodies much better since there will not be added pressure from pushing on them when loading a sample. All the pressure will be on the top plate, thus saving in future maintenance costs.


• Great option as there is two ways to inject a sample: by manual injection or having the PeriPump pull the syringe for you.

• Ideal for pulling the rinse solutions automatically into the system thus making the rinsing part of the operation much easier.

• Pressure mode available for carbonated samples.

• Has no added benefit to measurement performance over the Horizontal Load for an experienced user. However it benefits customers that have multiple inexperienced users as the PeriPump will automatically inject the sample the same way every time.

• No change in instrument’s performance when compared to HL or VL option.

MM Peri Pump

• Most versatile option. Allows three ways to inject the sample: through the supplied needle, manual injection or having the PeriPump (LA).

• Has no added benefit to measurement performance over the Horizontal Load for an experienced user. However it benefits customers that have multiple inexperienced users as the PeriPump will automatically inject the sample the same way every time.

• An added benefit is the cleaning process, or possible lack of cleaning and going right into your next sample which will decrease operational times.

• Yields same results as a VL or HL or LA for all non-viscous types of samples, so no change in performance occurs.

Syringe Injection

Samples can be easily loaded in the DDM series Density Meter by directly injecting your sample into the inlet port of the DDM. You can watch the sample progress through the U-Tube and monitor for bubbles. Need a closer look? View at 2X, 6X or 10X magnification. When your measurement is complete simply flush the U-Tube with your choice of solvent and use the convenient air tube to dry the U-Tube.

Who Should Use this System?

Laboratories who make only a few measurements per day. Users who wish to use very small amounts of sample – Only 1ml of sample is required.

Peristaltic Pump

Combining a Peristaltic Pump with a Rudolph Density Meter makes sample loading and cleaning faster and more convenient. A Peristaltic Pump draws the sample into the Density Meter and could also load a Refractometer. The user drops a tube into the sample and starts the Peri Pump from the DDM display. The Peristaltic Pump draws the sample through one or two instruments and then measures. The measured sample is displaced to waste by the following sample.

Who Should Use this System?

Laboratories working with low viscosity samples such as beverages.

Users who don’t mind utilizing 50 ml of sample for a measurement. A large amount of sample is needed to ensure all of the previous sample is displaced with the new sample.

AutoFlex R837 Automation System

The DDM Series of density meters can be combined with various Rudolph Automation Systems and Sample Handling Accessories.
Available are Peristaltic Pumping, Heated Sampler, the ECS (Easy Clean System), and the Rudolph R837 AutoFlex Sampler.

The Rudolph Research R837 AutoFlex is perfect for high throughput laboratories
looking to increase productivity.

The R837 AutoFlex Sampler Facilitates:

• Customizable bottle size, Test Tube size, Boston Rounds:1oz, ½ oz, virtually any size

• Customizable Rack configurations: heated and unheated on the same carousel
• Automated sample introduction

• Flexible Method Selection: Suction mode, Pressure mode, Rinse and Dry Duration

• Programmable cleaning and drying

• Automatic solvent and waste level detection

• System Configuration minimal sample volume: 1.5 mL

• A heated interface is available

• Fast throughput.

• Automation saves operator time and increases your lab’s efficiency
• An urgent-sample interruption can be made at any time

Operation is completely automatic. The sample is measured and the data recorded. Depending on how the system is configured the data may also be printed, saved as an Excel file or transferred to a LIMS system

Full Automation

Multiple measurements from one sample, with full automation and automatic cleaning and drying.


Combine instruments with Automation to Measure: Refractive Index, BRIX, Density, Specific Gravity, Optical Rotation, Color, Alcohol % vol/vol, Proof and more all from a single sample.

AutoFlex gives you the most flexibility in sample vial selection, sample handling and instrument combinations.

Ideal for high throughput Flavor, Fragrance, Alcohol, Chemical, Petroleum, Food Labs who run many samples each day and want automatic cleaning of the system.


By measuring Specific Gravity and Refractive Index the alcohol % by vol/vol can be determined for many products. This is a fast, single sample load solution for the Alcopops, Wine and Beer industries. The process of pre-distilling samples to remove the alcohol and adding back distilled water to replace any solids is eliminated. Simply load a sample into the system, the system measures the sample and using the AlcoTest software calculates the alcohol %.

AlcoTest®-RI-J209 is ideal for

 High volume producers of Alcopops products with high solids and/or high sugar based flavorings

 Producers of wine who wish to quickly measure alcohol % by vol/vol

 Producers of beer and other malt beverages

 Distilled Products with Obscuration

For alcohol % by vol/vol the following accuracies apply

better ±0.01 % v/v with DDM 2911 PLUS – TTB Compliant for high proof spirits

better ±0.04 % v/v with DDM 2911

better ±0.07 % v/v with DDM 2910

For obscured products, accuracies will vary by product. Ask for a demonstration or sample study.

Scientific Solutions

Scientific Solutions have been providing carefully selected laboratory and analytical equipment to Australian Industries such as Environmental, Pharmaceutical, Food and Beverage and Research markets of the Science Industry for over a decade.

Please enter your name.
Please enter a message.