Dr C Narain Spantech Products, South Godstone, Surrey, UK The exclusive representative for ACD in Europe, Middle East and India
ACD History Founded in 1988 Based in Tucson, AZ Our goal is to research, develop and manufacture dependable, accurate, reliable and affordable gas calibration standards. ACD have become experts and leaders in the calibration industry. ACD manufactures and distributes the most advanced hand held gas generators available to calibrate corrosive gas sensors
ACD Product range The CAL2000 The MiniCal The MiniBump
Benefits of ACD Products Instruments are small, light weight, durable and dependable. Gas is generated electrochemically as needed, not stored until used, so instruments do not degrade over time. Safe to ship, use, store and dispose of. Our instruments save the customer time and money
Current solutions for toxic calibration gases Calibration gas cylinders Unstable over even relatively short time Leads to short shelf lives Leads to uncertainty over actual concentrations Fixed concentrations Bulky One type of gas per cylinder
Current solutions for toxic calibration gases Permeation tubes Highly temperature dependent. High power consumption. Cannot be turned on and off. Mainly for laboratory use.
Electrochemical gas production Faraday’s law: “The amount of chemical change during electrolysis is proportional to the charge passed”
Variable parameters Current supplied Use an accurate and controllable current source with microprocessor control (for CAL2000) Amount of air blended with the gas generated in the cell Miniature mass/flow controller Maximise the reaction efficiency
What determines the reaction efficiency? Electrolyte Must be stable with time and replenishable Electrodes Must resist oxidation (or reduction) Must be able to carry sufficient current. Cell body Must not leak Should help to maintain stable cell environment Must be mouldable.
Other issues Gas is produced in bubbles We need to control the bubble size to maintain a smooth and repeatable output. Gas/electrolyte separation The electrolyte must be separated from the electrolyte prior to mixing in air, so that it will not escape into the electrolyte bulk. We use a Teflon membrane to separate the air mixing chamber
Advantages of Electrochemical Generation Can change concentration and flow rates by changing currents and mixing rates. A large amount of gas can be produced from a solid or gas. Can switch reaction on and off. Cells will last for years (if designed properly). Cells (and instruments) are small and compact. Low power consumption.
Advantages of Electrochemical Generation Interchangeable cells. Can be used in hazardous environments. No temperature dependency. Can use an inert balance gas. Can monitor reaction voltages to check the reaction efficiencies.
Disadvantages of Electrochemical Generation Limited number of gases. Pressure sensitivity. Can be expensive on short-term.
The CAL 2000 Unmatched versatility and accuracy in corrosive calibration gases. Field replaceable electrochemical generating cells. Microprocessor controlled.
One instrument - many gases! One instrument will generate: Chlorine Chlorine Dioxide Hydrogen Hydrogen Cyanide Hydrogen Sulphide Bromine
The CAL 2000 is the most cost effective method of providing calibration gases. The CAL2000 provides 50X the amount of gas per £ vs cylinders
CAL2000 Features Ease of use LCD Display Field adjustable PPM and flow rate Hand held design Low power consumption Micro processor controlled operation Safety features: Cells do not degrade over time. Automatic purge on shutdown Built in mass-flow sensor that compensates for altitude and temperature Suitable for both diffusion and sample drawn systems
Latest News!! CSA certified CAL2000 now available. All sensors factory calibrated to NIST standards Coming soon: Bromine Ammonia
Specifications Chlorine - 0.5 to 50ppm Chlorine Dioxide - 0.5 to 5.0ppm Hydrogen - 0.5-50ppm Hydrogen Cyanide - 0.5 to 50ppm Hydrogen Sulphide - 0.5 to 50ppm Note: PPM is variable with flow rate, output given at 0.5 Lpm. Useful cell time: 50 hours Warm up time (to 90%) approx. 5 minutes Weight: 3 Lbs Accuracy: +/- 10% Repeatability: +/-5% Operating temperature: 0 to 50 °C Battery life 25-30 hours
Customer comments We like your instrument and will recommend to all our customers as a reliable and easy operative source for generating Chlorine Dioxide and other gases" - Natasha Portman, Interscan Corporation” Thank you A.C.D., for setting a new standard in chlorine gas samples." - Terry Hebert, Dow Chemical, U.S.A.” The MiniCals are from Heaven" - Erkki Semi, Sarlin, Finland” We appreciate the personalised service" - Q.E.C., U.S.A.