Programmable Calibrator Procal 28532
The ProCal 28532 is a portable, battery-operated, precision instrument designed to provide fixed as well as programmable % millivolt or milliamp signals for quick calibration of a variety process control loops and control systems. It can also power a 24V DC 2-wire transmitter while measuring its current output. In addition, it can calibrate a loop from the field end using its own or loop power. It incorporates a continuous source of millivolts or milliamps with a 3½(4½) digit LCD indicator which can be set to a desired value. Its four % settings (% of the chosen value) allow quick calibration of many instruments including the industry standard 4-20mA input instruments. It is designed with a negligible warm up time so that the user can prolong the specified battery life by switching it on only when needed. It retains its precision over long periods of time in adverse environmental conditions.
The 28532 is designed with field-proven circuit blocks using low-power integrated circuits. It operates on 7 AA size dry cells, AA size rechargeable Ni-Cd cells or an external Battery Eliminator. The battery voltage is monitored to provide low-battery indication. A current limited DC/DC converter provides operating power to the circuitry for operational safety in hazardous locations. The DC/DC converter also provides a current limited 24V DC power for powering two-wire transmitters. With its unique operating controls and output terminals it can be used as a constant current regulator or transmitter simulator in 2-wire loops. The measuring circuit takes into account all possible error sources to ensure error-free measurement of the sourced or measured signal. A precision 3½ (4½) digit A/D converter provides a stable display with excellent repeatability.
The ProCal has two operating modes, viz. FS (Factory Set ) and US (User Settable). In the FS Mode, two (%1 and %2) switches provide precise outputs of 0%, 50%, 56.25% or 100% of 4-20mA & 0-200mV full-scale. In the US Mode, the User can vary the outputs continuously and can also use the same % switches to provide outputs for any signal value in the range of 0-200mV or 0-20mA. In addition, it has a provision for True/Live Zero outputs in both the cases for quick calibration of a variety of instruments. Both the modes are usable with the internal 24V DC power or loop power of upto 30V DC making it a versatile instrument which can be used either in the laboratory or in the plant for in-situ calibration of two-wire instruments and mA Loops. It is especially suitable for Manufacturing Shops and Field Commissioning Cells.
OUTPUT SPECIFICATIONS
The ProCal 28532 provides continuous as well as fixed % mV/mA outputs for quick calibration of Process Control Instruments and Loops. It can also simulate a 2-wire transmitter and 24V DC power to a 2-wire transmitters while measureing its output.
Xmitter Power
Upto 25 mA from 24( + 10% )V DC at 90% Battery Voltage
I/O Options
The Table below lists ranges available to meet most common requirements
| I/O Code |
Function and Range Switches |
Resolution |
| A(3½) |
200/20mA LZ/TZ (0, 50, 56.25, 100)% FS/US |
1 in 2,000 |
| B(3½) |
200/20mV/mA LZ/TZ (0, 50, 56.25, 100)% FS/US |
1 in 2,000 |
| D(4½) |
200/20mA LZ/TZ (0, 50, 56.25, 100)% FS/US |
1 in 20,000 |
| E(4½) |
200/20mA LZ/TZ (0, 50, 56.25, 100)% FS/US |
1 in 20,000 |
| G(4½) |
2V/200mV FS/US |
1 in 20,000 |
| Custom Ranges and % outputs |
Notes:
1. US - User Settable full-scale, FS - Factory Set full-scale
2. 0%, 50%, 56.25%, 100% are Factory Calibrated %s of US/FS full-scale.
3. These settings are obtained by two Switches marked as %1 & %2
|
Output Impedance
Less then 1 MO
Source Capacity
Upto 25 mA into 600O or 20mA into 800O @ 90% Battery Voltage
INPUT SPECIFICATIONS
Input Impedance
1/10O, option dependent
Input Protection
Input/Output Terminals Protected for 30V in mV & double the range in mA Mode
INDICATOR SPECIFICATIONS
Indicator Type
Indicators with the following resolutions to suit the selected Range
| 3½ digit |
: |
12 mm LCD with a resolution of 1 in 2,000 |
| 4½ digit |
: |
8 mm LCD with a resolution of 1 in 20,000 |
INSTRUMENT ACCURACY
Accuracy at operating temperature between 22-32 °C, valid within a one year Calibration Cycle
| 3½ digit |
: |
±0.05% of rdg ±0.02% of f.s. ±1 dgt |
| 4½ digit |
: |
±0.02% of rdg ±0.01% of f.s. ±2 dgt |
| Self-Check |
: |
Displays 1777±1 for 3½ and 17777±2 for 4½ dgt indicator |
POWER SUPPLY SPECIFICATIONS
Power Supply Options
| Option A |
: |
7 Nos of AA size dry cells giving 10.5V |
| Option B |
: |
7 Nos of Ni-Cd Rechargeable AA cells giving 8.4V |
|
Low Battery
Indicated by lighting all decimals or "LO BAT" indicator
Mains Operation
A Jack is provided for operation on an external Battery Eliminator
ENVIRONMENTAL SPECIFICATIONS
| Rated Temp |
: |
5 to 55 °C |
| Humidity |
: |
Less than 90% RH ( Non-Condensing ) |
| Zero Drift |
: |
Less than 1dgt for every 10°C beyond the specified ambient of 22 - 32 °C |
| Span Drift |
: |
Less than 0.0015% of rdg / °C |
| Storage Temp |
: |
0 to 70 °C (Without Batteries & Accessories) |
MECHANICAL SPECIFICATIONS
| Enclosure Size |
: |
125(W) x 200(H) x 60(D) mm |
| Enclosure Finish |
: |
Powder coated |
| Enclosure Weight |
: |
1.0 Kg (Without Batteries) |
STANDARD ACCESSORIES
Battery Eliminator, Probe Set, Leather Case, Wooden Case, Instruction Manual, Warranty Certificate, Calibration Certificate Traceable to NPL.
Charger for Ni-Cd Cells if Power Supply Option B is selected.
ORDERING INFORMATION
While ordering please specify the various options as per the following ordering code
| Model No. |
I/O Code |
P.S. Code |
| 28532 |
X |
X |
Example
Specify 28532AA to order the ProCal with 3½ digit 12mm LCD display, a range of 0-20 and 0-200 mA operating on 7 Nos of AA size dry cells. The output can be continuously variable with a provision of quick settings of Live Zero or True Zero signals of 0%, 50%, 56.25% and 100%. |
