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Mark 20 Water Quality Analyzer

Original price $11,750.00 - Original price $11,750.00
Original price
$11,750.00 - $11,750.00
Current price $11,750.00

Delivery time

In stock and ready to ship

The Ultrapure Water Quality Analyzer that started it all. 

The Martek Mark 20 Ultrapure Water Monitor provides laboratory accuracy in a multi-channel, multi-parameter on-line instrument for continuous monitoring of high purity water quality. Designed for maximum flexibility and ease-of-use, the Mark 20 provides real-time measurement of up to eight separate parameter inputs to permit custom configurations for a variety of process applications.

Data is displayed in direct engineering units on the large front panel readout while simultaneous digital and analog signals are available for external recording instruments or control devices. 

The Mark 20 includes a manual, mounting brackets and a power cord.

p/n 180-10






Sensor Type


0 to 100℃

0.01 ℃

±0.05 ℃ 

Thermolinear array


0 to 2.0000 µS/cm

0 to 20.000 µS/cm

0 to 20.00 µS/cm

0 to 200.0 µS/cm

0 to 200.0 µS/cm

0 to 2000.0 µS/cm

0.0001 µS/cm

0.001 µS/cm

0.001 µS/cm


0.01 µS/cm


±0.001 µS/cm

±0.01 µS/cm

±0.01 µS/cm

±0.1 µS/cm

±0.1 µS/cm

±1 µS/cm

2-element cell

Type 316 SS



0 to 14 pH units

±1400 mV 

0.01 pH units

±1.0 mV 

±0.1 pH units

±10.0 mV 

Combination glass electrode with double junction reference

HI, H2SO4 or NaOH

0 to 10% by weight



2-element insertion-style cell. Type 316 SS

*NOTE: The accuracy of conductivity measurements is dependent on appropriate cell constant in the scale of measurement and on the quality of the electrode.


User-selectable 120 / 240 volts AC, 50 / 60 Hz with fuze protection and 12 volt DC hookup

Printer Output

Serial ASCII RS232C standard. Isolated analog outputs of 0 - 1, 0 - 5 volts, or 4 - 20mA DC full scale for each parameter optional

Alarm Output Signals

DPDT Relay Contact Closures rated for 3 amps at 120 volts

Case Dimensions

9.70 inches (24.6 cm) width x 4.90 inches (12.5 cm) height x 13.0 inches (33.0 cm) depth behind front surface panel

Case Weight

18.5 pounds (8.4 kg)


Hardware supplied for panel or bench mounting


NEMA 12 aluminum enclosure coated to MIL SPECS

Manufactured in



Part Number



Mark 20 Monitor (eight channel) with RS232 serial output signal


Analog Recorder Output Circuit Board (eight channel) with 0 -1, 0 - 5 volt or 4 - 20mA output per channel 


Conductivity Flow-thru Sensor with preamp for ranges 0 - 2 & 0 - 20 µS / cm 


Conductivity Flow-thru Sensor with preamp for ranges 0 - 20 & 0 - 200 µS / cm 


Conductivity Flow-thru Sensor with preamp for ranges 0 - 200 & 0 - 2000 µS / cm 


pH Sensor Assembly with preamp


ORP Sensor Assembly with preamp


NaOH (Caustic) Insertion Cell with preamp


H2SO4 (Acid) Insertion Cell with preamp


HCI (Acid) Insertion Cell with preamp


Type 316 SS Flow Chamber for pH / DO sensor

NOTE: All prices FOB Factory and include the following warranties against defects in materials or workmanship: Analyzer and Preamps- 5 years, Conductivity Sensors - Lifetime. Consult the factory for specific warranty information. Specifications and prices subject to change without prior notice. 


- Easily calibrate and monitor up to eight channels
- Quick-disconnect terminal strips for adding or changing sensors to analyzer
- Slide-out chassis for calibrating analog outputs or for trouble-shooting


- Capable of remotely monitoring up to eight channels of conductivity and pH
- Automatic sensor detection at each of its eight channels and whether or not that channel has been correctly calibrated for that type of sensor
- Dual alarm set points at each configurable channel. Channels are continually scanned for alarm conditions. An alarm light on the front panel activates whenever any of the monitored channels recognize an alarm state.
- Well-lighted display presenting temperature, raw parameter data, and temperature-corrected parameter data simultaneously. This important feature allows the operator to immediately determine whether changes in parameter values are due to constituents in the process stream or simply temperature fluctuations.
- User-selectable temperature compensation formulas plus slope compensation for conductivity and pH measurements eliminate the need for additional modified circuitry or computer-generated correction factors.The Mark 20 resident processor easily applies these scientific formulas mathematically to the final readout measurement.
- Autoranging is performed on each of the three sets of dual conductivity ranges as well as through the set of four dissolved oxygen ranges.
- Differential analysis between any two channels of the same parameter provides instant performance evaluation of system efficiency for components such as dearators or condensate polishers.
- Standard RS232 digital serial port can be augmented with user-selectable analog outputs of 0 -1, 0 - 5 volt, or 4 - 20 mA for each separate channel. Up to ten Mark 20's (80 channels) can be multiplexed to one personal computer. The Mark 20 can even accept analog signals from other parameter analyzers and convert them to a digital output as well as indicate the data on its display.


The Martek Mark 20 includes the following items:
- Mark 20 Eight Channel Analyzer
- Mounting Brackets
- Power cord


The ability to collect, process, and transmit real-time data make the Mark 20 ideal for:

- Nuclear and Fossil Fuel Power Generation
- Condensate polishing Systems and Demineralizers
- Semiconductor Fabrication
- Pharmaceutical Manufacturing plants
- Other Industrial applications where ultrapure water monitoring is essential

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