TY - GEN
T1 - Laboratory evaluation of conductivty sensor accuracy and temporal consistency
AU - Maupin, Travis P.
AU - Agouridis, Carmen T.
AU - Barton, Christopher D.
AU - Warner, Richard C.
PY - 2012
Y1 - 2012
N2 - The focus on specific conductivity (EC25°C) in the Appalachian Coal Belt Region of the U.S. has highlighted the need to obtain accurate EC25°C measurements, particularly in light of the U.S. Environmental Protection Agency (USEPA) guidance that water discharged from mine sites in this region should have EC25°C levels less than 300-500 μS cm-1. Being able to accurately determine the EC 25°C levels of mine discharged waters has significant implications for the USEPA as well as mine operators particularly when EC 25°C levels approach this designated threshold. Presently, a number of sensors are available on the market for recording EC 25°C measurements; however, a detailed study comparing sensor performance under controlled conditions (e.g. temperature and EC 25°C levels) has not been performed. The objectives of this paper were to 1) evaluate sensor measurement stability over time (i.e. consistency) and 2) evaluate sensor accuracy of four commonly used sensors YSI 6600 V2-4 data sonde, HOBO U-24-001, Solinst Model 3001 LTC Levelogger Junior, and In-situ Aqua TROLL 100 at seven temperatures, ranging from 0 to 35°C, for six NIST traceable EC25°C standards, ranging from about 5 to 10,000 μS cm-1. Results indicated that three of the four sensors recorded consistent EC25°C values over time for the majority of the given temperatures while the Onset HOBO U24-001 displayed temporal fluctuations for most of the temperatures. Pair-wise comparisons demonstrated that these temporal fluctuations were present most often at the highest EC25°C tested, 10,000 μS cm-1. With regards to accuracy, the Onset HOBO U24-001 consistently overestimated EC25°C values while the other sensors tended to underestimate EC25°C values. Examination of the individual sensors within each sensor types revealed that in many instances at least one sensor performed quite differently than the others of the same type. As such, careful attention should be paid to individual sensor performance, particularly when the sensor is used for regulatory enforcement.
AB - The focus on specific conductivity (EC25°C) in the Appalachian Coal Belt Region of the U.S. has highlighted the need to obtain accurate EC25°C measurements, particularly in light of the U.S. Environmental Protection Agency (USEPA) guidance that water discharged from mine sites in this region should have EC25°C levels less than 300-500 μS cm-1. Being able to accurately determine the EC 25°C levels of mine discharged waters has significant implications for the USEPA as well as mine operators particularly when EC 25°C levels approach this designated threshold. Presently, a number of sensors are available on the market for recording EC 25°C measurements; however, a detailed study comparing sensor performance under controlled conditions (e.g. temperature and EC 25°C levels) has not been performed. The objectives of this paper were to 1) evaluate sensor measurement stability over time (i.e. consistency) and 2) evaluate sensor accuracy of four commonly used sensors YSI 6600 V2-4 data sonde, HOBO U-24-001, Solinst Model 3001 LTC Levelogger Junior, and In-situ Aqua TROLL 100 at seven temperatures, ranging from 0 to 35°C, for six NIST traceable EC25°C standards, ranging from about 5 to 10,000 μS cm-1. Results indicated that three of the four sensors recorded consistent EC25°C values over time for the majority of the given temperatures while the Onset HOBO U24-001 displayed temporal fluctuations for most of the temperatures. Pair-wise comparisons demonstrated that these temporal fluctuations were present most often at the highest EC25°C tested, 10,000 μS cm-1. With regards to accuracy, the Onset HOBO U24-001 consistently overestimated EC25°C values while the other sensors tended to underestimate EC25°C values. Examination of the individual sensors within each sensor types revealed that in many instances at least one sensor performed quite differently than the others of the same type. As such, careful attention should be paid to individual sensor performance, particularly when the sensor is used for regulatory enforcement.
KW - Appalachia
KW - Coal mining
KW - Water quality
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U2 - 10.21000/jasmr12010359
DO - 10.21000/jasmr12010359
M3 - Conference contribution
AN - SCOPUS:84878157162
SN - 9781622769339
T3 - 29th Annual National Conference of the American Society of Mining and Reclamation 2012, ASMR 2012
SP - 359
EP - 375
BT - 29th Annual National Conference of the American Society of Mining and Reclamation 2012, ASMR 2012
T2 - 29th Annual National Conference of the American Society of Mining and Reclamation 2012, ASMR 2012
Y2 - 8 June 2012 through 15 June 2012
ER -