duration, and are capable of being calibrated by the end user with known standards.
These instruments also feature multiple communication options for setup, calibration, deployment configuration, data downloading, and connection to a DCP or
telemetry system (e.g., Bluetooth, RS-232, SDI-12, RS-485).
Over the past 60 years, electronics and sensor technology have advanced from
analog to digital, resulting in more stable electronics and higher sensor accuracies.
This in turn has resulted in instruments that are more accurate (due to reduced
signal interference), hold their user calibration longer without drift, and have
become more widely accepted as alternatives to laboratory analysis. These
advances have also resulted in the advent of smart sensors. Smart sensors typically
will have a microprocessor in the same sensor housing as the sensing electronics,
making them digital instruments that store their own calibration, allowing them to
be transferred from one multiparameter instrument to another without the need to
recalibrate. Some of these smart sensors can even be connected directly to a DCP, in
some cases negating the need for a multiparameter data sonde all together.
Fig. 15 Examples of handheld water quality instruments for discrete measurements. Source: YSI
and Xylem [with permissions from YSI and Xylem]
Fig. 16 Examples of multi-parameter water quality instruments and smart sensors for continuous
monitoring. Source: YSI and Eureka [with permissions from YSI, Xylem and Eureka]
196
T. Younos and C.J. Heyer
These instruments also feature multiple communication options for setup, calibration, deployment configuration, data downloading, and connection to a DCP or
telemetry system (e.g., Bluetooth, RS-232, SDI-12, RS-485).
Over the past 60 years, electronics and sensor technology have advanced from
analog to digital, resulting in more stable electronics and higher sensor accuracies.
This in turn has resulted in instruments that are more accurate (due to reduced
signal interference), hold their user calibration longer without drift, and have
become more widely accepted as alternatives to laboratory analysis. These
advances have also resulted in the advent of smart sensors. Smart sensors typically
will have a microprocessor in the same sensor housing as the sensing electronics,
making them digital instruments that store their own calibration, allowing them to
be transferred from one multiparameter instrument to another without the need to
recalibrate. Some of these smart sensors can even be connected directly to a DCP, in
some cases negating the need for a multiparameter data sonde all together.
Fig. 15 Examples of handheld water quality instruments for discrete measurements. Source: YSI
and Xylem [with permissions from YSI and Xylem]
Fig. 16 Examples of multi-parameter water quality instruments and smart sensors for continuous
monitoring. Source: YSI and Eureka [with permissions from YSI, Xylem and Eureka]
196
T. Younos and C.J. Heyer