B - Probe Deployment - Hanna Instruments HI 98194 Instruction Manual

D.O. Sensor Maintenance (only for HI 98194 and HI 98196)
For a top performance probe, it is recommended to replace the membrane every
2 months and the electrolyte monthly.
Proceed as follows:
• Unscrew the membrane by turning it counterclockwise.
• Rinse a spare membrane with some electrolyte while
shaking it gently. Refill with clean electrolyte.
• Gently tap the cap over a surface to ensure that no air bubbles remain
trapped. Avoid touching the membrane.
• With the sensor facing down, completely screw the cap clockwise. Some
electrolyte will overflow.
If any deposit scales the sensor, gently brush the sensor surface with the supplied
brush, while paying attention to not damage the plastic body. Do not use the brush
on the membrane.
EC Sensor Maintenance (only for HI 98196 and HI 98195)
• After every series of measurements, rinse the probe with tap water.
• If a more thorough cleaning is required, clean the sensor with the supplied
brush or a non-abrasive detergent. Ensure that the two cylindrical holes in the
sensor are free of foreign material.
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APPENDIX B - PROBE DEPLOYMENT
The Hanna HI 769819X have been designed for a variety of water quality
measurements both in situ or in active deployments in urban or natural waters.
The HI 9819X systems may be used for discrete spot sampling with a meter
and the meter's log on demand function or, unattended with continuous
monitoring and logging from the meter. These data are then downloaded to a
meter or PC and can be plotted with logging software to obtain the graphical
log needed for interpretation of the essential physical property of the aqueous
body of water.
In all of these deployment situations data quality is dependent upon the site
location, service intervals, amount of coatings, sedimentation and vegetation,
and the actual installation. The probe may be installed in a horizontal bank
(fixed installation) or a vertical suspension. The maximum depth rating of 20 m
(65') for the probe should be adhered to. (Note: actual sensor specifications
may be less). The location must be accessible for the duration of the measurement
(consider seasonal flooding, freezing and other acts of nature) when selecting a
site. Many conditions may affect the quality of measurements. Select an
installation site that is representative of the water body being monitored. Avoid
areas without adequate water circulation. To protect equipment it is best to avoid
exposure to wind, foam, turbulence, air temperature gradients/sun, extended
periods of high flow, extended periods of high sediment and floating debris. The
standard operating procedures (SOP) for the data gathering must be upheld.
This typically includes pre and post deployment checks of the sensors to validate
data gathered between calibrations, upholding service intervals, and following
any other site-specific procedures. Grab samples for laboratory analysis or spot
sampling with another probe are addition ways to validate the measurements
taken by unattended continuous logs.
The probe is suitable for installation in confined locations such as air vaults, river
intakes, vertical wells, tanks, etc.. The streamline diameter of the probe permits
insertion into 2" pipelines. Unlike probes that require a cable support for active
deployments the probe can be manually lowered and raised by the cable due to
it's superior strength member.
It is suitable for installation in open moving waters; rivers, streams, ditches
(farmland drainage), conveyance canals, etc.. In these cases protecting the probe
from debris is important. If the probe is suspended from a pier or bridge position
it behind a support and anchor the cable/probe to a pipe.
It is suitable for deployment in open waters; monitoring lakes, ponds, wetland
basin, infiltration basins, bays. Schedule regular service to remove aquatic weed
growth that may be interfering with representative water samples.
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