One embodiment provides a system, including: at least two water analyzers, wherein at least one of the at least two water analyzers is positioned upstream of a purification apparatus and wherein at least another of the at least two water analyzers is positioned downstream of the purification apparatus; at least one processor; and a memory device that stores instructions executable by the processor to: receive water analysis data from the at least two water analyzers, wherein the water analysis data comprises information related to membrane integrity; identify an algorithm for calculating membrane integrity based upon received data corresponding to system attributes; and calculate, using the identified algorithm, the membrane integrity based upon the received water analysis data. Other aspects are described and claimed.

A reagent dispenser includes a housing. A container of microbial inhibitor is disposed within the housing. A dispensing system is disposed within the housing and operable to dispense the microbial inhibitor from the container. The dispensing system is calibrated to dispense a calibrated weight per water sample of the microbial inhibitor, such that a ratio of the calibrated weight per water sample to inner volume of a sample bottle substantially equals a predetermined concentration of microbial inhibitor per liter of water determined to acidify water to a pH of 4 or less.

Systems and methods for analyzing groundwater samples with multiple organic tracer species from a petroleum containing reservoir include obtaining the sample, isolating an aqueous fraction of the groundwater sample, separating the aqueous fraction into a plurality of components, where each component corresponds to a different one of the organic tracer species, combining each of the separated components with at least one lanthanide element to form a plurality of component solutions, where a ratio of the at least one lanthanide element to the separated component in each component solution is 5:1 or greater, and analyzing each component solution to determine a relative amount of each organic tracer species in the groundwater sample.

An optical water quality sensor includes a holder base having a first light-transmitting portion and a second light-transmitting portion extending in the same direction, a first receiving groove and a second receiving groove respectively extending into the first light-transmitting portion and the second light-transmitting portion and a first light-condensing side and a second light-condensing side respectively located on the inner sides of the first light-transmitting portion and the second light-transmitting portion, and a sensor module with a circuit board assembled in the accommodating space. The circuit board has a first arm plate and a second arm plate respectively inserted into the first receiving groove and the second receiving groove, and a light emitter and a light receiver respectively located on the first arm plate and the second arm plate to face the first light-condensing side and the second light-condensing side.

An optical water quality sensor includes a holder base having a first light-transmitting portion and a second light-transmitting portion extending in the same direction, a first receiving groove and a second receiving groove respectively extending into the first light-transmitting portion and the second light-transmitting portion and a first light-condensing side and a second light-condensing side respectively located on the inner sides of the first light-transmitting portion and the second light-transmitting portion, and a sensor module with a circuit board assembled in the accommodating space. The circuit board has a first arm plate and a second arm plate respectively inserted into the first receiving groove and the second receiving groove, and a light emitter and a light receiver respectively located on the first arm plate and the second arm plate to face the first light-condensing side and the second light-condensing side.

A system for sensing analyte in at least partly translucent material, including one or more radiation sources configured for successively providing radiation at a first and a second wavelength, respectively, two or more waveguides for simultaneously transmitting the radiation at each wavelength provided by the radiation source, a first waveguide being a reference waveguide and a second being a sensing waveguide; and measuring means for measuring a phase difference between the radiation waves from the reference waveguide and the measuring waveguide, resp. The present method can be used for measuring contaminants such as Fe, Sn, and/or Pb in oil related products, such as carburant or lubricant.

A system for sensing analyte in at least partly translucent material, including one or more radiation sources configured for successively providing radiation at a first and a second wavelength, respectively, two or more waveguides for simultaneously transmitting the radiation at each wavelength provided by the radiation source, a first waveguide being a reference waveguide and a second being a sensing waveguide; and measuring means for measuring a phase difference between the radiation waves from the reference waveguide and the measuring waveguide, resp. The present method can be used for measuring contaminants such as Fe, Sn, and/or Pb in oil related products, such as carburant or lubricant.

A residual chlorine meter for measuring the concentration of residual chlorine in sample water includes an indicator electrode and a counter electrode to be immersed in the sample water and a controller that measures the concentration of residual chlorine in the sample water based on a diffusion current flowing between the indicator electrode and the counter electrode in a case in which a voltage is applied between the indicator electrode and the counter electrode. The controller detects a degree of deterioration of a replaceable component of the residual chlorine meter based on a motor current, flowing through a motor that rotates the indicator electrode in the sample water, and/or the diffusion current.

A residual chlorine meter for measuring the concentration of residual chlorine in sample water includes an indicator electrode and a counter electrode to be immersed in the sample water and a controller that measures the concentration of residual chlorine in the sample water based on a diffusion current flowing between the indicator electrode and the counter electrode in a case in which a voltage is applied between the indicator electrode and the counter electrode. The controller detects a degree of deterioration of a replaceable component of the residual chlorine meter based on a motor current, flowing through a motor that rotates the indicator electrode in the sample water, and/or the diffusion current.

Detection and sampling of dissolved hydrocarbons of interest in an environment expected to have hydrocarbon molecules, such as a water column or interstitial water in sediment. An apparatus comprising at least one oleophilic film frame is deployed into the environment and the at least one oleophilic film frame is exposed thereto for a defined period of time, and thereafter isolated from the environment to cease exposure thereto. Hydrocarbon molecules scavenged by the oleophilic film may be analyzed to determine their type and/or concentration.