1. A RFID tag comprising
a receiver input section for processing signals from a RFID reader, said receiver input section including an RF detector for converting signals received from a designated RFID reader to a baseband signal, including corrupted baseband signal segments attributable to noise or other RF interference on the received signal,
a data comparator for comparing the level of said baseband signal including any said corrupted baseband signal segments to a threshold level and for generating a data output representing portions of said baseband signal exceeding said threshold level,
a processor responsive to the baseband signal for tracking its signal level including the level of said corrupted baseband signal segments and for generating an adaptive level as said threshold level for said comparison, whereby to produce a comparator data output substantially free from said corruption, and
wherein said processor includes a peak signal detector and an amplifier with selectively adjustable gain for scaling the peak signal detected by said peak signal detector as said threshold level for said comparison.
2. The RFID tag of claim 1, wherein said processor includes an averaging circuit for tracking variations in the level of said baseband signal over selected intervals of time.
3. The RFID tag of claim 2, wherein said processor includes an amplifier with selectively adjustable gain for scaling the tracked variations of said baseband signal level as said threshold level for said comparison.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A concentrated solution for photographic reversal baths, comprising:
a) stannous ions,
b) a chelating agent comprising an alkali metal salt of phosphonic or phosphinic acid, and
c) a biological growth control agent,
wherein said biological growth control agent comprises a mixture of at least one quaternary ammonium compound of formula (I) and at least one polymeric quaternary ammonium compound of formula (II),
R1(R2)N(R3)R4X(I)
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wherein R1, R2, R3 and R4 are independently nonpolymeric aliphatic, heterocyclic or carbocyclic radicals,
X is a halide,
R5 and R6, which can be the same or different, each represent an alkyl radical of 1 to 4 carbon atoms, optionally substituted with an hydroxyl group,
A represents a divalent hydrocarbon radical of 1 to 10 carbon atoms, said divalent hydrocarbon radical being substituted with at least one hydroxyl radical,
n is an integer of from 2 to 100,
and wherein the total concentration of quaternary ammonium compounds (I) and (II) is less than or equal to 0.5 gl.
2. The solution of claim 1 wherein the concentration of quaternary ammonium (I) and (II) is less than or equal to 0.1 gl.
3. The solution of claim 1 wherein the chelating agent comprising an alkali metal salt of an organic phosphonic or phosphinic acid is obtained from a concentration more than or equal to 125 gl of the corresponding phosphonic or phosphinic acid and a corresponding metal base.
4. The solution of claim 1 wherein the concentration of stannous ions is more than or equal to 20 gl.
5. A ready-to-use reversal solution for photographic reversal bath, comprising
a) stannous ions,
b) a chelating agent comprising an alkali metal salt of phosphonic or phosphinic acid, and
c) a biological growth control agent,
wherein said biological growth control agent comprises a mixture of at least one quaternary ammonium compound of formula (I) and at least one polymeric quaternary ammonium compound of formula (II),
R1(R2)N(R3)R4X(I)
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wherein R1, R2, R3, R4, R5 and R6, X, A, are as defined above,
the concentration of quaternary ammonium (I) and (II) being less than or equal to 10 ppm.
6. The ready-to-use solution of claim 5 wherein the total concentration of quaternary ammonium compounds (I) and (II) is less than or equal to 5 ppm.
7. The ready-to-use solution of claim 5 wherein the concentration of stannous ions is more than or equal to 0.6 gl.
8. The ready-to-use solution of claim 5 obtainable by the dilution in water of the concentrated solution according to any of claims 1 to 4.
9. The solution of claim 1 or 5 wherein X is a chloride.
10. The solution of claim 1 or 5 wherein the quaternary ammonium (I) is selected from the group consisting of nonyltrimethylammonium chloride, dodecyl-trimethylammonium chloride, hexadecyltrimethylammonium chloride, benzyltriethylammonium chloride, benzyldimethylphenylammonium chloride, tetrahexylammonium chloride, a benzalkonium chloride, a mixture of alkyltrimethylammonium chlorides, or mixtures thereof.
11. The solution of claim 10 wherein the quaternary ammonium (I) is a mixture of dodecyl-, tetradecyl- and hexadecyl-dimethylbenzyl-ammonium chlorides.
12. The solution of claim 1 or 5 wherein A is
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13. The solution of claim 12 wherein the polymeric quaternary ammonium (II) is poly(2-hydroxyethylenedimethyliminio-2-hydroxypropylenedimethyliminiomethylene)dichloride.
14. The solution of claim 1 or 5 wherein said phosphonic or phosphinic acid is represented by formula (III) or (IV),
R7N(CH2POzM2)2(III)R8R9C(POzM2)2(IV)
wherein z is 2 or 3,
R7 is selected from the group consisting of hydrogen, an alkyl group of 1 to 12 carbon atoms, an alkylaminoalkyl group wherein each alkyl group has 1 to 12 carbon atoms, an alkoxyalkyl group of 2 to 12 carbon atoms, a cycloalkyl group of 5 to 10 carbon atoms in the ring, a 5- to 10-membered heterocyclic group having one or more nitrogen, oxygen or sulfur atoms in the heterocyclic ring, or CHR10POzM2.
R8 is selected from the group consisting of hydrogen, an alkyl group of 1 to 12 carbon atoms, an aryl group of 6 to 10 carbon atoms in the aromatic ring, a cycloalkyl group of 5 to 10 carbon atoms in the ring, a 5- to 10-membered heterocyclic group having one or more nitrogen, oxygen or sulfur atoms in the heterocyclic ring, POzM2 or CHR10POzM2,
R9 and R10 are independently selected from the group consisting of hydrogen, a hydroxy group, an alkyl group of 1 to 12 carbon atoms, or POzM2, and
M is hydrogen.
15. The solution of claim 14 wherein the chelating agent comprising an alkali metal salt is an alkali metal salt of aminotris(methylenephosphonic) acid.
16. The solution of claim 1 or 5 wherein it comprises a p-aminophenol as stannous ion stabilizer.
17. The solution of claim 1 or 5, being free of propionic acid.
18. The solution of claim 1 or 5, containing the combination of acetic acid with an acetate as buffering agent.
19. A method of processing an exposed color reversal photographic film comprising the circulation of said exposed film in a ready-to-use reversal solution according to any one of claims 5 to 18, and the color development of said film.