The cone tip is pushed to the specified sample depth and the tip dislodged. The water sampler, connected to a dual range bladder pump, is then passed down the rod string. Using a ‘squeeze’ technique, the bladder pump operates with gentle purging and sampling to fill the 500ml sample containers with the groundwater. The controller allows the user to match the pumping rate to the well recharge rate, limiting the stress on the formation: a maximum stoke volume of 95ml enables a maximum pump rate of up to 1.45 litres per minute. The bladder pump also has applications with low flow purging and sampling whic are required with flow rates as low as a few millilitres a minute.
The water sampler works well alongside Lankelma’s membrane interface probe (MIP) to take groundwater samples where contamination has been detected.