Electro-Chemical Devices (ECD) SMS22 - Manual (Page 39)

Fill a two liter volumetric flask about 2/3rds full with distilled water. Stir the water with a magnetic stir
bar. THE SOLUTION MUST BE STIRRED WHEN ADDING the KOH or OVERHEATING WILL OCCUR. Slowly
add approximately 100 grams of the KOH and allow it to dissolve. Cool in an ice bath to 30°C or lower
and add the second aliquot of approximately 100 grams of the KOH. Stir until dissolved, cool in ice bath
to 30°C or lower and add the balance of the KOH, 120 grams. Cool to room temperature and bring to 2
liter volume with distilled water before adding to the Carboy Container. The SMS-22 carboy has a 10
liter capacity, 5 x 2 liter batches.
Reagent #2 (7.5% Hydrochloric Acid)
CAUTION dissolving Hydrochloric Acid in water is an exothermic reaction, it gets HOT. Use caution to
avoid overheating and splattering of this highly acidic reagent.
Materials Needed (2 liters) Amount
Hydrochloric Acid, ACS Grade, 37% (HCl)
CAS Number 7647-01-0
400 ml
Distilled Water
CAS Number 7732-18-5
2 liters (to volume)
This is a 5:1 Dilution, 1 part HCl 37% and 4 parts distilled water.
Fill a two liter volumetric flask about 2/3rds full with distilled water. Stir the water with a magnetic stir
bar. Slowly add approximately 200 ml of the HCl. Cool to below 30°C and slowly add the second aliquot
of approximately 200 ml of the HCl. Cool to below 30°C and add the balance of the HCl. Cool to room
temperature add bring to 2 liter volume with distilled water before adding to the Carboy Container. The
SMS-22 carboy has a 10 liter capacity, 5 x 2 liter batches.
Appendix C
Scaling Lascar 4-20 mA loop powered indicator
The Lascar DPM 742-BL gives an accurate, zero adjusted indication of a 4-20mA current. Calibration is by
two multi-turn potentiometers which allow sensitive adjustment of the instrument over a very wide
range. Decimal points are jumper link selectable. LED backlighting ensures excellent readability under
low light conditions. Connection is via screw terminals. This module is supplied with a plastic mounting
bezel. A waterproof seal to IP67 /NEMA4X is achievable,
using the optional BEZ 700-IP metal bezel. A low drift
band gap reference circuit ensures accurate readings
over a wide temperature range.
See www.lascarelectronics.com for more information.
SMS-22 Page 30