Danfoss AKS 41 Liquid Level Transmitter
Publication 9-45
Section 9
Page 16 of 18
Issue 1 : 10/11
12.
Adjustment (Early Version)
12.1.
Setting AKS 41 for the Refrigerant (Early Version)
Same as the later version of the AKS 41; refer to 6.1. The red LED
‘flashes’ when the transmitter is in setting mode.
12.2.
Calibration for Minimum Liquid Level (Early Version)
(a)
There is a shorting strap provided at one of the two pins provided
for calibration of 4 to 20 mA output signal. Place this strap across
the two pins so they are short-circuited. The liquid level transmitter
is now in calibration mode: green LED extinguished, red LED
‘flashing’.
(b)
Bring the liquid refrigerant to the level corresponding to the lower
limit of the measuring range, i.e. the point on the rod where the
transmitter’s output signal is to be 4 mA. The full length of the rod
should be used if possible, so calibrate the lower limit with the
liquid level below the end of the rod.
(c)
Press the calibration push-button then release within 3 seconds.
The green LED will illuminate when the button is pressed.
Wait 10 seconds. The new minimum calibration has been saved to
memory.
(d)
Unless the calibration of the maximum liquid level is to be carried
out, remove the shorting strap from across the two pins and store
by placing over one of the two pins.
12.3.
Calibration for Maximum Liquid Level (Early Version)
(a)
Normally, maximum calibration is done after minimum. If this is not
the case, carry out 12.2 step (a) first.
(b)
Bring the liquid refrigerant to the level corresponding to the
maximum limit of the measuring range. i.e. the point on the rod
where the transmitter’s output signal is to be 20 mA. The full
length of the rod should be used if possible, so calibrate the upper
limit with the liquid level 45 mm below the top of the rod (measured
from the top gasket’s contact face).
(c)
Press the calibration push-button then release within 3 seconds.
The green LED will illuminate when the button is pressed.
Wait 10 seconds. The new maximum calibration has been saved
to memory.
(d)
Remove the shorting strap from across the two pins and store by
placing over one of the two pins.
12.4.
Calibration for Minimum and Maximum Points Other Than 4 mA and
20 mA (Early Version)
The usual minimum and maximum calibration points are 4 mA and
20 mA, however, the transmitter can be calibrated at other points within
the signal range. This facility is especially useful if it is impractical to
bring the liquid level to the maximum and minimum limits.
It is necessary to measure the 4 to 20 mA output signal. Dismantle the
cap on the DIN connecting plug and pull it back a little on the cable to
gain access to the four screw terminals inside the plug where the four
wires are connected. Connect a meter between terminals 2 and 3 so that
the 4 to 20 mA output signal can be measured.
There is a shorting strap provided at one of the two pins for calibration of
4 to 20 mA output signal. Place this strap across the two pins so they are
short-circuited. The liquid level transmitter is now in calibration mode:
green LED extinguished, red LED ‘flashing’.
