DTC Test Kits FAQ
Please read below for answers to some of the most frequently asked questions about our DTC Test Kits and how they work. If you have any additional questions, we’re happy to help. Simply visit our Contact page and get in touch. Our team will respond as soon as possible.
If a metering pump is being used to feed DTC into the pretreatment system, a mathematical calculation may be used to drop the residual DTC concentration down to an acceptable level. It’s usually a good idea to maintain a “safety margin” of residual DTC within the waste stream of about 100 ppm. If a test of the effluent water yields a DTC concentration of 250 ppm, for instance, and the metering pump is running at a rate of 100 BPM, turn down the pump to the 100 ppm level by using the following equation:
New Pump Speed = Current Pump Speed X 100 ppm / 250 ppm
New Pump Speed = 40 BPM
It’s also recommended to run lab jar tests (beaker tests) on samples of wastewater in order to determine the accurate volume of DTC to add prior to running the batch.
If after reacting with the color indicator the sample begins to coagulate, precipitate or is much darker than usual, the digital colorimeter will immediately exhibit a warning display that the sample is OVER the limit. The analog test kit will peg out at over 100 ppm and the titration syringe will have to be reloaded several times should a sample be higher than 200 ppm. If the reacted sample is too high while using immersion test strips, the sample color will be much darker than the color comparator on the bottle. In all cases, samples can be diluted with distilled or deionized water and then the actual concentration determined by multiplying display by the amount of dilution. For instance, if it is necessary to dilute a sample down to 50% to get a reading, multiply the reading by 2 in order to obtain the true concentration. If it is necessary to dilute the sample down to 10%, multiply the reading by 10 to achieve the actual concentration.
Analog colorimeter kits measure DTC concentrations up to 100 ppm. Digital colorimeter kits can measure DTC concentrations up to 420 ppm. Test strip kits can measure DTC concentrations up to 1,000 ppm, however, they are less accurate than the other kits. Titration kits can measure up to 200 ppm but can be reloaded as many times as necessary, should a sample be higher than 200 ppm.
Digital colorimeters can measure DTC concentrations down to 1 ppm (part per million), which is similar to 1 mg per liter. Titration can measure DTC concentration concentrations down to 3 – 10 ppm, and the immersion test strips (which are for quick-reference only) measure DTC concentrations as low as about 50 ppm and as high as about 1,000 ppm.
Operators of industrial wastewater pretreatment systems, workers within the rubber vulcanization industries and EPA field technicians who are testing industrial discharge water or ground or river waters in which DTC is believed to have been spilled.
Our products include handheld colorimeter test kits (both digital and analog), direct-reading, volumetric titration test kits and immersion, color-comparator test strips.
DTC, sometimes referred to as DMDTC, is an organic, sulfur-bearing carbamate pesticide, fungicide and herbicide. DTC’s full name is Sodium Dimethyldithiocarbamate. While it was developed by the Union Carbide Company as a pesticide, it has become widely used as a metal ion reducing and coagulating agent in wastewater pretreatment within the electroplating, metal finishing and printed circuit manufacturing industries. It’s also used as a vulcanizing agent within the rubber processing industries.