PC 950 Probe Colorimeter User Manual
Contents
1. PC 950 Probe Colorimeter User Manual Description The PC 950 probe colorimeter measures the optical transmittance absorbance and concentration of liquids The fiber optic probe allows measurement s to be taken directly from containers and measurements can be made at different wavelengths by changing plugin filters Functions are selected by a front panel keypad and readings and settings are displayed an an alphanumeric LED display An RS 232 serial port comnecticn provides data to a remte PC Two analog output signals drive a strip chart recorder 0 0 V 1 0 V and or a 4 m 20 mA current logo for industrial applications Control Keys ON Tums the instrument an OFF Tums the instrument off MOD E Selects the operating mode Successive key presses set the instrument from Transmittance to Absorbance to Concentration to Setup and back to Trensmittance ZERO Calibrates to zero absorbance 100 0 transmittance ENTER Ih Setup ENTER either enters a submenu or allows parameter settings to be stored Ih Concentration ENTER saves the current concentration coefficient in memory t Tncreases a setting value in Concentration it increases the concentratia coef ficient and thus the reading y Decreases a setting value in Concentration it decreases the concentration coef ficient and thus the reading RETURN Causes the menu to back up cme level during Setup Instrument Operation Before tuming an the PC 9502. the 25 pin female D connector The 0 0 V 1 0 V output can be used to drive an analog strip chart recorder or other data acgquisiticn system Its atp impedance is nominally 750 ohms care should be taken not to load the output with less than 1 Mom 0 0 V represents a transmittance value of 0 and 1 0 V represent s a transmittance value of 100 The 4 mA 20 mA output can be used to drive an industrial omtrol system or other data acquisition system Typically ae would load the 4 mA 20 mA output with a 100 ohm 200 qm resistor to ground to dtain a praportianal voltage 4 0 mA represent s a transmittance value of 0 and 20 mA represents a tiansmittance value of 150 Setup Operation P2 PINOUTS P2 is the female 25 pin D comector an the rear parel It is used for both tte serial port and the analog atot firctins If aly the serial port is required a standard serial port cable can be used If analog ocutyuts are required a special cable must be faloricated If both serial ports and analog outputs are required then a special cable must also be fabricated The table below lxs pins and their functions All other pins are not connected Serial port to receive data ipt RI Serial port to transmit data output TX Clear to send CIS set to 0 mark A EII Tedmical specifications Display resolutian Two analog output s RS 232 output Power input Dimensions W egt POWER OPTIONS The PC 950 requires 12 V DC
3. 25 pin D connector is provided at the rear of the instrument To comect the instrument to a PC comect a serial cable with a 25 pin male to the colorimeter and a 9 pin or 25 pin male depending an the serial port an the PC to the PC end These cables are available at computer suppliers Use a serial communication program such as Windows HyperTerminal or Kermit to establish communications Make sure the correct COM port is being used Set up the baud rate of the communications program to match the instrument The default setting is 9600 baud Set up the hardware flow control handshake to NONE With these settings made and the colorimeter on and comected to the PC colorimeter values will be displayed on the computer screen The output data is the sane as the front panel display The table below shows the cutyut data format h Concentration the decimal point is in the same positim as the frat panel display Serial Input The instrument responds to single character ASCII commands in the same way 1t responds to keypad keys The ASCII commands to which the instrument responds are listed in the following table ASCII Input Key or Command ep woe ef ek la pown a a Oe oe M ae a ae te seno ANALOG OUTPUTS Two analog outputs are provided from the colorimeter 0 0 V1 0 V and 4 mA 20 mA which are both proportional to the tranamitt ance readings of the instrument These outputs are provided from pins an P2
4. averaging AVERAG Set concentration decimal point format Set serial baud rate Set lamp voltage Test menu
5. select and ital the agorqomiate filter for the test that will be conducted Install the fiber qotic probe into the lamp and filter holder making sure the knurled screws are finger tight to prevent relative motion between fiber aptic and the instrument ON OFF Press the ON key to start When the FC 950 is first timed an it displays PC 950 followed by the firmere revision and then enters the Trensmittance mode and autozeroes itself It is nw ready for operation when operation is complete tum the PC 950 off by pressing OFF TRANSMITTANCE OPERATION Transmittance displays the qotical tiansmittance of a measured sample from 0 0 to 100 0 The transmittance display fomet is T 100 0 Totake a reading zero the instrument to 100 T 0 0 A by placing the instrument probe in a reference liquid standard or distilled water depending an the procedure and pressing ZERO The instrument should now read T 100 0 absorbance value of w Place the probe in the sample to be measured and its trensmttance value can be read on the LED display ABSORBANCE OPERATION Absorbance displays the ootical absorbance of a measured sample from 0 000 to 2 000 corresponding to transmittances of 100 0 to 1 0 respectively Absorbance is calculated as the negative base 10 logaritim of transmittance LOG10 T The Absorbance display format is A 0 000 To display absorbance press MODE util te Absorbance display format appears Totake a r
6. at 500 mA The wall transformer provides this power from the AC lire Altemetively 12 V DC power can be provided to the instrument To power the instrument from 12 V apoly a source of 12 V via a 5 5 x 2 1 mm coaxial power connector The center pin is positive and the out side is negative The PC 950 requires a stable source of between 12 0 V DC and 14 0 V DC capable of providing 500 mA The PC 950 is protected against reverse polarity Transmittance 0 1 Absorbance 0 001 units OV1iVIC 4 mA 20 mA 25 pin 0 5 A 12 Y DC Transformer provided for either 110 V or 220 VAC 8 0 x 5 5 x 2 5 in 20 3 x 14x 16 3 cm 3 2 1b 1 5 kg a paro Y 3A Key Operation ON OFF Powers the unit m or cof FON displays the model and the firmware revision MODE Selets tte Operating mode in the main menu scrolls down the menu MAIN Power on model SW revision Transmittance Absorbance Concentration Use t On ENTER gp to Setup Set averaging 1 measurement every 4 seconds 1 measurement every second 1 measurement every 1 4 second Quick Reference Command Sheet DN E DE ENTER Goes to the submenu or saves settings When entering a submenu the t Goes to the next higher menu item Concentration value can be increased 4 Goes to the next lower menu item Ih Concentration value can be decreased RETURN Retums to the higher level menu RETURN RETURN will alwys reum to the main menu Set
7. eading zero the instrument as dae in the Transmittance mode ih Absorbance the instrument should read A 0 000 Nte thet tte ZERO antrol ffets all instrument modes and zeroing in any of the modes has the same ef fet Place the probe in the sample to be measured and its absorbance value can ke read on the LED display CONCENTRATION OPERATION The Concentration mode displays the concentration of a measured sample Concentration is calculated by multiplying the absorbance reading by a coef ficiet which is set by calibrating with a sample of a known concentration and then adjusting the instrument to display that amoentratian To accommodate a very wide range of values the decimal point of the display can also be set using Setup To calibrate concentration first zero the instrument as described above Then set the instrument to Concentration mode using the MODE key The Concentration display for met is C 0000 Place the probe in a sample of know concentration For example if the reference solution concentration is 20 0 awd its absorbance is 0 300 and 4 should be pressed until a reading cf C 0200 appears Press ENTER to stoe this setting To change the decimal point to read C 020 0 see Setup Operation an the following pages Place the probe in a sample to ke measured and its amoentration value can be read from the display Setup Operation Setup allow a user to set the following instrument parameters concentratio
8. n decimal point display position serial port baud rate measurement averaging and lamp voltage setting In addition the instrument can ke reset to its factory default settir DS To enter Setup press MODE util SETUP appears on the display Press ENTER The display will disolay AVERAG which is the display to enter the Average Setting mode To change the average setting press ENTER To set another parameter press Y a Lu thet parameter is displayed and then press ENTER Other parameters are AVERAG CON DP BAUD LAMPV and TEST When the desired setting for the parameter is displayed pressing ENTER sets t parameter and the setting will remain in nonvolatile memory when the unit is tumed off or the power is removed RETURN allows tte unit to rtm to Setup without changing any settings This can be used to view possible settings and the current setting The first setting displayed in a menu is the current setting READING AVERAGE SETTING AVERAG This setting is used to change the number of display readings per second The instrument averages one or more measurements The settings are AVE 1 AVE 4 ad AVE 16 forl 4 ad 16 measurements respectively Each measurement is 1 4 of a second which results in readings of every 1 4 second 1 every second and 1 every 4 seconds Lower averaging results in faster response ime readings per second and slightly higher noise reading to reading variaticn Higher averaging results in slowe
9. r response time and lower noise The factory default stig is AVE 4 or 1 reading per second CONCENTRATION DECIMAL POINT SETTING CON DP This setting is used to change the display positicn of the decimal point in the Concentration mode This conveniently allows you to display concentration in AN PECOS eee XX PESA XXX The factory default setting is XXXX SERIAL PORT BAUD RATE SETTING BAUD This setting is used to change the serial communication baud rate The settings are B 4800 B 9600 and B19200 for 4800 9600 and 19200 baud respectively The factory default setting is B 9600 or 9600 baud LAMP VOLTAGE SETTING LAMP V This setting is used to change the lamp volt age setting to ae of three settings LAMP H LAMPM LAMPL ferir to lamp voltages of high 6 5 V medium 6 0 V ad low 5 5 V respectively High can cause the lamp to wear cut prematurely which would require more frequent lamp replacement High is used when solutions are optically dense or a selected filter is qtically dense Low E used when a filter is qotically transparent Medium is the falt setting TEST FACTO RY DEFAULT SETTING TEST Use this setting to reset the instrument to its factory default settings Select the aly doice RESET adhit ENTER Tre unit will be reset to its factory settings Setup Operation SERIAL PORT OPERATION The RS 232 serial port can be used to cotain measurement data ar to aantral the instrument settings P2 a
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