Reliable and Economical Molybdate Analysis

The Hach MO42 Molybdate Analyzer uses colorimetric catechol chemistry to continuously monitor a sample stream for molybdate content. This process analyzer is a dependable and economical alternative to costly, time-consuming laboratory analysis methods.

Manual or Automatic Feed Pump Control

Chemical feed can be manually or automatically controlled by either the alarm relay contacts or the proportional 4-20 mA recorder output. When set for manual control, the instrument notifies the operator of out-of-limit molybdate levels for manual intervention in the process as needed. For automatic control of molybdate feed pumps, the MO42 analyzer can use one of two methods: 1. On-Off Control—turns the feed pumps on when molybdate levels fall too low for sample treatment and off when levels rise above a pre-set limit. 2. Proportional Control—adjusts the amount of molybdate in proportion to the signal level of the MO42 analyzer’s output.

Simple Maintenance

Routine maintenance can typically be performed monthly in 15 minutes because the sample cell and pre-filter are easy to clean and the case provides quick access. （Difficult samples, i.e. turbid or oily samples, may require more frequent cleaning.） The MO42 analyzer is also equipped with self-testing diagnostics to make troubleshooting easy.

Method of Analysis

Available molybdenum ions react with pyrocatechol （catechol） at buffered pH to form a yellow colored complex compound. After the chemical reaction is complete, the optical density （absorbance） at 420 nm is compared to the absorbance of the sample measured before the reagent was added. The depth of intensity of the resulting color is proportional to the concentration of molybdenum in the sample, which is calculated from the difference in absorbance values.

Applications - Industrial

The MO42 Molybdate Analyzer is ideal for industrial water treatment applications where it is necessary to continuously monitor and control the concentration of molybdate within specified levels—cooling towers and closed recirculating systems, such as hot water heating （boilers） and chilled water systems （coolers）. Molybdate compounds are used extensively in these areas as corrosion inhibitors or as tracer agents for the determination of concentrations of other treatment chemicals. It is important that the concentration of molybdate be maintained at the specified levels in order to balance the benefits of corrosion protection without the additional expenses of chemical overfeed. The Hach MO42 Molybdate Analyzer is an effective alternative to laboratory methods for molybdate monitoring and allows for real time feed control.

What's in the box

Hach MO42 Molybdate Analyzer, one-month supply of reagents, maintenance kit, installation kit, and user manual. （Power cord sold separay.）

Specifications

Accuracy:± 5 % or 0.05 mg/L ± 0.05 mg/L whichever is greater

Cycle Time:2.5 min

Lower Limit of Detection （LOD）:0.03 mg/L

Operating Temperature Range:5 to 40 °C

Range:0 to 5 mg/L as Mo⁶⁺

Ranges:to as Mo⁶⁺

Shipping Weight:11.3 kg （25 lbs）