AC100 & AC420 High Accuracy Millivolt Amplifiers
AC100 and AC420 are high accuracy amplifiers that
are specially designed for use with thermopile sensors. The primary application is with
heat flux sensors, pyranometers, net-radiometers and pyrheliometers.
The specifications of both amplifiers are such that they can be used with the highest
class of this type of instruments, while ensuring that no accuracy is lost.
Also the amplifiers contain protection against
transients (useful in meteorological applications). In this sense,
AC100 and AC420 are unique. AC100 has a voltage output, AC420 has a 4 to 20
mA current output.
While the current output in some applications has the advantage of extra quality
assurance for cable breaks (current will go to zero), it has the disadvantage that it
cannot be used with input signals that can go both positive and negative, such as
net-radiometers and heat flux sensors in meteorological situations.
AC 100 & AC 420 FEATURES & BENEFITS
Extremely low zero offset and range drift over the entire temperature range. Adaptable sensitivity, by do-it-yourself mounting of ordinary metal film resistors Possibility of feeding through extra wires, e.g. from temperature sensors or more
voltage signals that are led through the same cable as the signal that must be amplified. Can be used with the highest accuracy lowest signal sensors without loss of accuracy. Suitable for outdoor installation.
SPECIFICATIONS
| |
AC100 |
AC420 |
| Typical sensors |
Heat flux plates Pyranometers
Net –radiometers
Pyrgeometers
Pyrheliometers
Albedometers
Connectors for wiring of additional temperature sensors are available inside AC 100
housing |
Pyranometers Pyrheliometers
Albedometers
Heat flux plates in applications with only one-way heat flux
Connectors for wiring of additional temperature sensors are available inside AC 420
housing |
| Minimal full scale input |
+/- 3 mV |
+ 3 mV |
| Maximum full scale input |
1000 mV |
1200 mV |
| Output |
Voltage between +3 and –3 Volt |
4 –20 mA current loop
(to 3.5
mA) |
Standard Amplification (A) |
200 |
1 mA/mV |
| Do-it –yourself adjustment of A by
resistor R |
A = (2*(50.000/R)+1 A from 1 to 1000. R
can be composed of 1 to 3 separate resistors in series. |
10 mV full scale, using 4 to 14 mA range R
= 100* full scale input
A from 16 mA/5 mV to 16 mA/1200 mV. R can be composed of 1 to 3 separate resistors in
series. |
| Example of R calculation |
R of 1000 ohm plus 10 ohm gives an A of
100. |
Heat flux sensor UT 03 delivers 4.56 mV an
1000 W/m2 heat flux. R of 456 ohms delivers 4 mA at zero input and 14 mA at 1000 W/m2.
AC 420 is only to be used if the heat flow does not
reverse / change sign. |
| Specifications of R |
1%, 50 ppm metal film resistor |
1%, 50 ppm metal film resistor |
| Input impedance |
1 Mohm |
1 Mohm |
| Ambient temperature range |
-20 to + 50 °
C |
-20 to + 50 °
C |
| Temperature range for storage |
-30 to + 70 °
C |
-30 to + 70 °
C |
| Zero drift at output |
< 0.05 mV/°
C |
< 0.25 m A/° C |
| Range drift at output |
< 20
ppm/°
C |
< 20
ppm/°
C |
| Initial accuracy |
0.1% |
0.1% |
| Power supply |
8 – 24 VDC |
10 – 24 VDC |
| Supply current |
< 20 mA |
n.a. |
| Loop voltage to output ratio |
n.a. |
< 10 m A / V |
| Output impedance |
< 10 ohm |
n.a. |
| Maximum load |
< 1 mA |
n.a. |
| Response time |
< 1 s |
< 1 s |
| Dimensions |
120 * 120 * 80 mm |
120 * 120 * 80 mm |
| Connection |
Swivels for cables from 4 to 6 mm diameter |
Swivels for cables from 4 to 6 mm diameter |
| Input protection |
Protected against static discharge,
reverse power |
Protected against static discharge,
reverse power |
| Options |
MA 220 mains adapter for 220
VAC. |
MA 220 mains adapter for 220
VAC. |
List of sensors with which AC 100 and AC 420 can be applied. Please note that
additional temperature sensors and signals carried through the same wire can be wired
through in the boxes of AC 100 and AC 420.
| Hukseflux HFP01 Heat flux sensor |
AC 100 in all applications, AC 420 in
applications in which the heat flow is one directional. |
| Hukseflux UT03 Heat flux sensor |
AC 100 in all applications, AC 420 in
applications in which the heat flow is one directional. |
| Hukseflux HFP01SC Self calibrating heat flux sensor |
AC 100 in all applications, AC 420 in
applications in which the heat flow is one directional. |
| |
|
| Kipp & Zonen CM21 Pyranometer |
AC 100 or AC 420 |
| Kipp & Zonen CM11 Pyranometer |
AC 100 or AC 420 |
| Kipp & Zonen CM6B Pyranometer |
AC 100 or AC 420 |
| Kipp & Zonen CM 3 Pyranometer |
AC 100 or AC 420 |
| Kipp & Zonen NR Lite Net radiometer |
AC 100 |
| Kipp & Zonen CG1 Pyrgeometer |
AC 100 |
| Kipp & Zonen CH1 Pyrheliometer |
AC 100 or AC 420 |
| Kipp & Zonen CM7B albedometer |
Two AC 100 or two AC 420 |
| Kipp & Zonen CM14 albedometer |
Two AC 100 or two AC 420 |
| |
|
| Eppley PSP Pyranometer |
AC 100 or AC 420 |
| Eppley PIR Pyrgeometer |
AC 100 |
| Epply NIP Pyrheliometer |
AC 100 or AC 420 |
| |
|
| TNO Heat flux sensor |
AC 100 in all applications, AC 420 in
applications in which the heat flow is one directional. |
| |
|
| Schenk Stern Pyranometer |
AC 100 or AC 420 |
| Schenk Net radiometer |
AC 100 |
| |
|
| Middleton CN3 Heat flux plate |
AC 100 in all applications, AC 420 in
applications in which the heat flow is one directional. |
| Middleton EP08 Pyranometer |
AC 100 or AC 420 |
| Middleton CN1-R Net radiometer |
AC 100 |
| |
|
| CSA CN3 Heat flux plate |
AC 100 in all applications, AC 420 in
applications in which the heat flow is one directional. |
| CSA CN1-R Net radiometer |
AC 100 |
| |
|
| REBS HFT 1 & HFT3 Heat flux plate |
AC 100 in all applications, AC 420 in
applications in which the heat flow is one directional. |
| REBS Q-7 Net radiometer |
AC 100 |
|
